A viral pandemic spreads across the world as medical organizations rush to track it and create a vaccine.
On Day 2, Beth Emhoff is waiting to board her flight home as she coughs. She receives a phone call from Jon Neal who calls her and says it was nice seeing her after mentioning meeting with her to have sex earlier and reminds her to use an alternate email address of his to communicate with him. Her flight is called and she hands her credit card to the waitress to close out her tab. In Kowloon, Hong Kong, Li Fai is riding a boat home and showing symptoms of suffering from a fever. He then takes a subway home and sits down on the couch next to Li Fai's Sister, who seems concerned about his condition. In London, England, Irina is also showing signs of a fever. She returns to work and drops off a portfolio before taking a taxi home where she is found by a maid having suffered a seizure. In Minneapolis, Minnesota, Beth signs paperwork dealing with a construction project and returns home where she is greeted by Clark Morrow and Mitch Emhoff. A Japanese Bus Man exits a plane lavatory and looks at paperwork from AIMM Anderson. As he is riding a bus in Tokyo, Japan, he suddenly collapses. Li Fai's condition continues to deteriorate and he rides an elevator with a family and walks out to the market area. He starts to get tunnel vision and walks out into the middle of the street and is hit by a truck.
On Day 3, Dr. Ellis Cheever arrives for work in Atlanta at the Centers for Disease Control and Prevention. He passes by Roger and tells him he did a good job picking the winners in the football betting pool. Roger asks Dr. Cheever if he could diagnose his son, Anthony with having ADHD, but Dr. Cheever tells him he isn't that kind of doctor, but could refer him to someone. In San Francisco, California, Alan Krumwiede shares a video on his blog of a phone recording a passenger took when the Japanese Bus Man collapsed. He then shows the video to Lorraine Vasquez and tells her it could be from mercury poisoning in the fish which the fishing industry suppresses. She tells him she will show it to their health reporter and Alan gets upset and threatens to sue the paper if they steal his story. Mitch goes to Clark's school to pick him up and the School Nurse walks Clark over to Mitch and tells Mitch, Clark was complaining about feeling warm. She tells Mitch she took Clark's temperature and it was over 100 degrees.
On Day 4, Beth is starting to experience tunnel vision. She drops her coffee cup and then collapses and starts suffering from a seizure. Mitch takes Beth to the hospital. Dr. Arrington talks to Beth as ER Nurse 1 asks Mitch if Beth has any history of seizures. Beth starts to Code Blue and ER Nurse 2 tells Mitch he has to leave the room. Later Dr. Arrington along with a Social Worker tell Mitch that Beth died. Mitch at first refuses to believe it and then starts to demand to know how Beth died. As he is returning home, Mitch receives a call from Carrie Anne and he tells her to hang up and call 911. He gets home and Carrie Anne tells him Clark said his head hurt so she sent him to bed. Mitch runs upstairs and finds Clark dead.
On Day 5, in Geneva, Switzerland, Dr. Leonora Orantes arrives at the World Health Organization. Damian Leopold updates her that the Chinese Government is saying an outbreak has been contained to the Chrysanthemum complex in Hong Kong. Meanwhile, Li Fai's Sister returns home to the Guangdong Province in China with his ashes. She is later found dead by a bus worker on the bus. A WHO Official asks Damian how the Chinese are defining contained. Dr. Orantes then warns them that due to the nature of Hong Kong, the virus will spread. Dr. Orantes mentions two outbreak clusters in London, a cluster in Tokyo and the WHO Official asks if any of the dead in Tokyo traveled to London or China. A Paramedic takes Jon Neal away in a stretcher as Jon Neal's Wife watches and tells Paramedic that both her and Jon woke up sick that morning and she is brought along into the ambulance. The Minnesota Medical Examiner and Assistant Medical Examiner perform an autopsy on Beth and the Minnesota Medical Examiner notices Beth's brain has some severe damage and tells the Assistant Medical Examiner to start calling everyone after telling him to step away from Beth's remains.
On Day 6, Dr. Erin Mears arrives at the CDC and she and Dr. Cheever discuss the outbreak in Minneapolis. She arrives in Minneapolis and meets Dave and they get started working immediately. Jory Emhoff arrives at the hospital after being dropped off by the Minnesota Department of Health. Helpful Doctor tells her, Mitch is in isolation, but she can talk to him with a phone. They talk and he reassures her that he is okay and he suggests she stay with her mother in Wisconsin, but she refuses. At the Minnesota Department of Health, Minnesota Health 1 tells the group there are 47 cases and 9 deaths as of current, but Minnesota Health 2 warns that the death and infection rate might be low due to it being the weekend and people are staying home. Dr. Mears brings up the terms fomites and after Minnesota Health 3 asks her to define it, she explains, fomites are transmissions from surfaces. Minnesota Health 4 doesn't want to release information to the press due to how the public might react. She brings up the time people were warned about Swine Flu and how it did nothing but scare people and reminds everyone that it is the largest shopping season of the year, Thanksgiving holiday. Minnesota Health 2 suggests they close down schools, but Minnesota Health 4 says people won't be able to work at the stores and will have to stay home with their kids. Dr. Mears goes to the dry erase board and writes down the Flu, Smallpox, and Polio with the numbers 1, 3 and 4/6 for each respectively. She explains the numbers represent the R-nought or the reproductive rate of the virus. At the CDC in Georgia, Dr. Ally Hextall and Dr. David Eisenberg are in the Biosafety Level 4 Laboratory examining a sample of Beth's tissue. Dr. Eisenberg asks how Dr. Hextall's Thanksgiving went and she tells him she working on a case in Texas dealing with a Salmonella outbreak. Dr. Hextall tells Dr. Eisenberg the virus is pleomorphic but tends towards ovoid in shape with glycoproteins on its surface. She then tells Dr. Eisenberg to send the sample to Dr. Ian Sussman in San Francisco. Dr. Sussman reports the virus shows novel characteristics and appears to be chimeric in origin with 15 to 19 kilobases in length and six to ten genes typical of paramyxovirus. Alan runs up to Dr. Sussman with a mini recorder and asks him if the virus was created by the military and tells Dr. Sussman there is talk on the blogosphere the virus is a biological weapon.
On Day 7, at the CDC, Dennis French walks up to Dr. Cheever and asks him to come with him to the emergency operations center to meet with RADM Lyle Haggerty. Dennis hands out photographs of the quarantine in Kowloon and talks about strikes in Macao where three people have died that lived in the same bunkhouse. Dennis says Homeland Security's concern is a terrorist contracting the virus on purpose to use as a terror weapon. Dr. Cheever asks what the three casino workers died of and it matches that of the victims in Minnesota. A newscaster reports the closing of the school Clark went to and the death of the School Nurse. Dr. Mears and Dave go to the offices of AIMM Alderson and interview AIMM Employee 1, AIMM Employee 2, AIMM Employee 3, and AIMM Employee 4. AIMM Employee 2 tells her he opened a package Beth sent, AIMM Employee 3 tells Dr. Mears she and Beth did Pilates together before she got sick, and AIMM Employee 4 tells Dr. Mears he and Beth had coffee the day before she left. Dr. Mears asks if Beth had contact with anyone else and after AIMM Employee 1 tells her no, he is corrected and Dr. Mears is told Aaron Barnes had contact with Beth after she returned from her trip. Dr. Mears calls Aaron and she notices he has a cough, and asks where he is. When he tells her he is on a bus, she tells him to get off immediately. Aaron gets off the bus and is picked up by Dr. Mears and Dave. Dr. Mears asks Mitch questions about Beth and when she mentions Beth had a long layover in Chicago, Mitch mentions that Beth once had a relationship with someone named Jon Neal and he figures out Beth was cheating on him. Dr. Hextall tells Dr. Cheever the virus contains bat and pig genetic sequences. Dr. Cheever tells Dr. Hextall to have any other researcher with samples to destroy them. She calls Dr. Sussman and tells him he has to destroy his samples.
On Day 8, Dr. Cheever gives a news conference listing the effected cities and Alan writes down information on a notepad. Dr. Orantes arrives in Hong Kong and meets with Sun Feng. They interview a person in the hospital and look at a group of possibly connected cases. Damian holds a video meeting with world officials and tells them he believes there are 89,000 cases in the world and heading towards 267,000. Dr. Cheever tells the people in the video meeting that they haven't figured out a way to grow the virus in cells yet. A Japanese Official asks if the CDC found any treatment or antivirus yet, and Dr. Hextall tells him no. Dr. Orantes and Sun Feng track Beth's movements to Macao. She notices Village Man 1 and Village Man 2 talking loudly and Sun Feng tells her they are from his village and they found a new cluster there and his mother has symptoms of the virus. Dr. Sussman is at a restaurant and notices people touching their mouths and feeding their kids as a customer coughs. Later when he is in the lab, Sussman's Assistant tells him she heard they are shutting them down from working on the virus and he tells her to go home and he will destroy their samples. Later, Dr. Hextall tells Dr. Cheever, Dr. Sussman managed to grow the virus in his lab.
On Day 12, a newscaster reports that the CDC and WHO revealed Dr. Sussman was successful in growing what they are calling the MEV-1 virus in a laboratory setting. Alan has a meeting with Hedge Fund Man in Park and Alan tells him forsythia will be talked about in the media soon as a cure for MEV-1. Mitch finds out he is immune to MEV-1, but Dr. Mears tells him Jory can still get sick due to her receiving part of her DNA from her mother. As Mitch and Jory are leaving the hospital, they pass a man demanding to know if the hospital has forsythia. Dr. Mears and Dave inspect a gymnasium they can use to make a makeshift hospital and Minnesota Health 4 asks if the cost of the hospitals are coming out of the CDC's budget or the state's. Dr. Cheever calls Dr. Mears and asks her how she is doing. Mitch is watching the news as a TV Anchor reports over 3000 cases of the MEV-1 virus in the area. He hears the doorbell ring and runs over and stops Jory from answering the door for Andrew. Andrew tries to leave some flowers as condolences for Beth and Clark, but Mitch tells him to take them with him. Dr. Orantes watches the recordings from the casino and watches as Beth interacts with people, including blowing on the dice of Japanese Bus Man. She shows the clip to Chinese Health Official 1 and Chinese Health Official 2. She suggests the virus started in Hong Kong, but they tell her she doesn't have enough evidence to suggest it came from Hong Kong.
On Day 14, Dr. Mears wakes up coughing and after realizing she probably has MEV-1, calls the hotel and tells them to gather the names of all hotel personnel that she had contact with or cleaned her room. She then calls Dr. Cheever and tells him she is sick and he promises to get her help. Funeral Director tells Mitch they can't take any of the MEV-1 bodies due to insurance issues with their employees and union. Mitch tells Beth's Mother the funeral home won't bury her. The video recording from the casino continues and Beth is shown calling Jon Neal and scheduling a rendezvous with him. As she buys more drinks, Irina notices Beth leave her cellphone on the counter and Irina hands it to her. Sun Feng says it doesn't prove anything and asks about any contact with Li Fai. Dr. Orantes continues the video which shows Li Fai picking up one of Beth's used glasses. Dr. Orantes declares Beth the index patient to Sun Feng. Sun Feng tells Dr. Orantes about a rumor that the French and Americans have a cure for MEV-1 that they are manufacturing in secret according to the internet. She asks about his mother and he tells her she died even though they tried giving her forsythia. As Dr. Orantes is about to deliver the information to the WHO, Sun Feng calls someone and she is kidnapped. She is brought to Sun Feng's village as a hostage and he tells her she is going to be used so his village can go to the front of the line for any cure. In Minneapolis, Dave checks on Dr. Mears and gives her, her phone and tells her they are trying to move her, but the nurses' union are calling for a work stoppage until protocols are in place. Dr. Cheever tries to get Haggerty to evacuate Dr. Mears, but he refuses. He finally admits to Dr. Cheever that the plane used to evacuate personnel is being used to evacuate one congressman and then they are closing the airports and the President is to be moved underground. Alan makes a blog telling people he has caught MEV-1 and then takes a drop of forsythia, which he says has helped him fight off the virus. He tells his viewers if forsythia works, they will all know tomorrow. Dr. Cheever calls Aubrey Cheever and tells her how many people can die and then asks her to leave Chicago and go to Atlanta. Dr. Cheever hangs up the phone and Roger is standing outside his office and then leaves after telling Dr. Cheever he has family too. While shopping, Aubrey gets a call from Elizabeth Nygaard and tells her what Dr. Cheever told her.
On Day 18, at a pharmacy, a long line of people wait to get forsythia, including Lorraine. Coughing Man coughs and when Lorraine tells him to cover his mouth he tells her to "fuck off". The worker tells those in line there are only 50 doses of forsythia and the crowd panics and runs towards the supply of forsythia. Alan watches as the people in the store start to destroy it to get forsythia. Mitch and Jory go to the grocery store and find it being looted. Mitch encounters a Sick Lady who coughs on him and asks him for help. They try and drive into Wisconsin, but are told by National Guardsman to go back the way they came. Alan walks through a deserted San Francisco placing flyers telling people the CDC lies and forsythia is the cure. He finds Lorraine sick at his doorstep and she tells him she had a seizure and asks him for forsythia. In Minneapolis, Dr. Mears is laying on a hospital bed as Shivering Man asks a Nun for another blanket, but the Nun tells him they are out of blankets. Dr. Mears tries to hand Shivering Man her jacket, but lacks the strength and dies. Dave looks down at her dead body wrapped in a HAZMAT sheet and leaves some flowers. Her body is then placed along with many, in a mass grave. Morgue Worker walks up and asks Dave when they ran out of body bags and he tells him two days ago. Sanjay Gupta, MD conducts an interview with Dr. Cheever and Dr. Cheever suggests the best defense against MEV-1 is social distancing. Sanjay then interviews Alan who says forsythia is effective against MEV-1 and accuses the WHO of working with pharmaceutical companies. Dr. Cheever and Alan argue and Alan mentions a Facebook post by Elizabeth which she attributes to Dr. Cheever concerning the quarantine of Chicago, before it was announced to the public. After the interview, Haggerty tells Dr. Cheever the government is looking for a scapegoat and Dennis walks into the office and tells Dr. Cheever there will be an investigation into whether he told people about the quarantine ahead of time.
On Day 21, Dr. Eisenberg is looking over data and calls Dr. Hextall. She tells Dr. Cheever their sample of MEV-1 has mutated and increased its reproduction rate. Dr. Cheever holds another meeting and tells those present the MEV-1 now has a mortality rate of 25 to 30 percent with a new R-nought of 4. As Alan is walking he sees a photo of Lorraine among those that have died from MEV-1.
On Day 26, in Minneapolis, Minnesota, as Mitch is waiting in line for MRE's, a Man with Megaphone tells those in line they have exhausted their supply for the day and the crowd charges at the supply trucks. A newscaster tells the audience the death toll has reached 2.5 million in the United States and the President has ordered mandatory curfew. Mitch hears gunshots from his neighbor's house and sees two masked men run out of the house.
On Day 29, Mitch goes to various neighbor's houses to look for supplies. He finds most of his neighbors gone. He returns home and finds Jory making snow angels with Andrew and pulls Andrew away from Jory and tells him to go home. Dr. Cheever asks Dr. Hextall if they are close to a vaccine, but she tells him no and wishes him a Merry Christmas. Dr. Hextall arrives at work and sees Vaccine 57 Monkey still alive from a successful vaccination. She then tests the vaccine on herself. She goes to a hospital and exposes herself to a sick Hextall's Father after telling him she is testing her vaccine. A newscaster reports the FDA is fast tracking the approval of the MEV-1 vaccine to stop MEV-1, which has killed 26 million people.
On Day 131, Aubrey is home as Home Invasion Thug breaks into Dr. Cheever's house and he demands to know where the vaccine is. Dr. Cheever gets home and she tells him about Home Invasion Thug. Alan has another meeting with Hedge Fund Man in Park and tells him, he isn't the only one to make money off of a viral outbreak. Hedge Fund Man in Park mentions studies show forsythia doesn't cure MEV-1. Alan then says the vaccine may cause unknown side effects and brags that he can convince people not to take the vaccine. Alan notices a sanitation worker paying attention to their conversation and asks Hedge Fund Man in Park if he is wearing a wire. Alan tries to run away, but is caught by authorities and Dennis tells him he is to be charged for securities fraud, conspiracy and manslaughter.
On Day 133, a lottery is held for the first vaccines and RADM Haggerty holds a news conference in which he gives credit to those who work on the vaccine. Dr. Cheever walks into the office and tells Dr. Hextall she should be enjoying her kudos for her work, but she brings up Dr. Mears and Hextall's Father who succumbed to the virus and Dr. Cheever who is to be hauled in front of a congressional hearing for warning Aubrey. Mitch and Jory are watching the news conference and Mitch assures Jory the government won't run out of vaccines. After finding out her number isn't one of the first ones to get the vaccine, Jory tells Andrew she has to wait another 144 days to see him. In Lan Tau, Dr. Orantes is teaching children when Sun Feng tells her they need to leave. They drive to Tsuen Wan Cemetery where Dr. Orantes is exchanged for doses of the vaccine. As they are waiting for their flight, Damian gives Dr. Orantes her vaccine and tells her the ones they gave to Sun Feng were placebos. She then gets up and leaves. Mitch goes to the mall while Dennis tells Alan his body showed not having any antibodies to MEV-1. Alan is then released on bail paid for by his supporters. RADM Haggerty gives Dr. Cheever his two doses of the vaccine and Dr. Cheever gives one to Aubrey and the other to Anthony, Roger's son and Anthony thanks Dr. Cheever and Roger shakes Dr. Cheever's hand.
On Day 135, Alan takes video of a vaccination center. Dr. Hextall and Dr. Eisenberg walk into a containment area and place MEV-1 into cold storage as mass vaccinations happen. Mitch picks up Beth's camera and scrolls through photographs of her trip to China. A now vaccinated Andrew and Jory have their long delayed prom dance.
In a flashback, an AIMM Alderson bulldozer is clearing land. As it knocks down a palm tree, a group of bats fly away. The MEV-1 Host eats a banana, but drops a portion of it into a pig pen, which is then consumed by a pig which is then prepared by a Chef who shakes hands with Beth...this is Day 1.