Howell is a medical doctor on The Walrus in the West Indies.
During the events of Black Sails: Season 1 Episode 1 I. played by Alistair Moulton Black
After a battle, Dr. Howell tells Captain Flint that Mr. Duffy has died.
During the events of Black Sails: Season 1 Episode 7 VII. played by Alistair Moulton Black
De Groot and Dr. Howell hold back Randall from attacking John Silver. De Groot tells Silver that the ship's council voted Randall off the crew. Randall Tells De Groot and Howell that Silver stole the page and not Singleton. De Groot tells Dufresne what Randall told him. Howell suggests they keep the information from the crew so that they can continue with their hunt of the Urca. Dufresne, De Groot and Howell go to get Silver after he fails his test and Silver pulls a knife on De Groot, who pulls his own knife out. Randall then starts calling everyone a thief.
During the events of Black Sails: Season 1 Episode 8 VIII. played by Alistair Moulton Black
As The Walrus is going through a storm, Dr. Howell gives Silver a fake leg for Randall to wear. The Walrus and Ranger arrive at Division Bay and Flint briefs his crew. Once they get view of the bay. no ship is there. Logan spots sails and yells it to the crew and yells out that the ship is a Man-o'-War. Silver yells at the Man-o'-War that they are being followed by a pirate ship and points at the Ranger. He tells the Spanish Officer where they came from and the Man-o'-War continues on its way. As Flint is about to give the order to fire on the Man-o'-War, Dufresne pulls a pistol on him and accuses him of tyranny against the crew. Dufresne holds up the letter Gates gave him which details Flint's crimes against the crew. As Flint goes to fire a cannon, Dufresne shoots him. Silver fires one of the cannons at the Man-o'-War and Flint tells Dufresne not to waste the moment. Dufresne freezes and the Man-o'War fires at The Walrus and Dufresne orders The Walrus to open fire. The Man-o'-War opens fire again and The Walrus is obliterated.
During the events of Black Sails: Season 2 Episode 1 IX. played by Alistair Moulton Black
Flint starts to tell The Walrus crew his plan. Logan angrily yells that they should be cutting Flint's lying tongue from his head and Dufresne tells the crew to listen to Flint. Flint suggests they steal the warship and then take the gold. He continues to tell his plan of sending two people to kill any sentries on the ship while the rest of the crew readies an assault. De Groot gets upset with listening to Flint's plan and Flint volunteers to be one of the men to kill the sentries and Silver volunteers to be the other. Later, Ranking Spanish Sailor looks towards the water and Joji shoots him in the head. Joshua breaks the door down where Flint and Silver are hiding and he and the rest of The Walrus crew kill the remaining Spanish crew. They then manage to steal the Spanish ship and escape.
During the events of Black Sails: Season 2 Episode 6 XIV. played by Alistair Moulton Black
Billy Bones walks into camp and is greeted by the rest of Flint's crew and Dufresne hugs him. Billy tells the pirates of The Walrus about his ordeal and that the British Navy is encamped 40 miles away. Dufresne then asks Billy how he fell overboard.
During the events of Black Sails: Season 2 Episode 10 XVIII. played by Alistair Moulton Black
Yardley has Baymen Lieutenant grab Silver and Flint's crew stand up to block them from leaving with Silver. Billy headbutts Yardley and a fight breaks out, but Silver is dragged away. As Jenks is about to slit Silver's throat, Flint's crew storm into the room and Billy kills Jenks while Yardley and Baymen Lieutenant are also killed. De Groot tells the crew to raise the sails and Mr. Scott tells them to get ready to sail. Billy has the crew fire upon the blockade ships. Flint and Captain Charles Vane get into a boat and start to row towards the Man-o'War and are fired upon by William Rhett and some militia men. The Man-o'-War opens fire on Rhett and kills him. Silver is brought to Dr. Howell who removes Silver's injured leg.
During the events of Black Sails: Season 3 Episode 1 XIX. played by Alistair Moulton Black
Dr. Howell tells Silver that Silver's wound is not properly healing and that he should use crutches instead of the boot. He then warns him that if Silver's wound doesn't heal correctly, Dr. Howell will have to remove more of Silver's leg.
During the events of Black Sails: Season 3 Episode 2 XX. played by Alistair Moulton Black
Flint sees Captain Benjamin Hornigold turn back and orders the topgallants to be taken down. Billy asks Rogelio if the halyard is free and Murtaugh tells him that it is stuck. Murtaugh climbs to the top of the mast to cut the halyard and the ship is hit by a knockdown wave. Some of the men are knocked overboard and De Groot tells Flint that they must take the topgallant in. Flint cuts a rope and part of the mast breaks away and goes flying away with Murtaugh.
Flint tells Billy to have everyone go down below while Flint stays on deck to steer the ship. Later, De Groot tells Flint that the storm drove them into the Sargasso Sea. Billy tells Flint that they lost most of their fresh water and they have very little food. Flint asks how far the nearest coast is and Silver tells him that they are three weeks from land.
During the events of Black Sails: Season 3 Episode 3 XXI. played by Alistair Moulton Black
On day 18 on The Walrus, Palmer and Oates are accused of stealing rations. Silver holds a trial to figure out which one of them stole the rations. Oates insists he would never steal from the crew. Palmer says that during everything that has happened, he has never complained. Flint walks up and shoots Palmer in the head and then starts to reload his gun. Flint then shoots Oates in the head.
On day 21, Billy tells Flint that they spotted a whale carcass. De Groot says that whale's float after they rot, but Silver insists they go after it and tells Flint he is coming also. Silver and Flint bring a shark back to the ship and feed the crew with it. After the wind returns, the crew of The Walrus arrive at an island and go ashore.
During the events of Black Sails: Season 3 Episode 4 XXII. played by Alistair Moulton Black
The pirates from The Walrus are gathering water and food on the island while also making camp. A group of Maroons capture the rest of The Walrus crew. As they are being brought to the Maroon camp, Silver's leg goes out from under him and Twitchy Pirate tries to escape. Flint and his crew are brought to a village where they meet The Maroon Queen who demands to know who their captain is. She asks Flint what his name is and then asks who their quartermaster is. Silver steps forward and The Maroon Queen asks him how they found the island and who else knew where they were. She asks him if he was in her position if he would take the word of a pirate and then has one of the crew taken away while the rest of them are placed inside a cage.
During the events of Black Sails: Season 3 Episode 5 XXIII. played by Alistair Moulton Black
A group of maroons carry Mr. Scott ashore on a stretcher and Billy, who can't see who it is, asks Silver who is on the stretcher. Ben Gunn tells them that Mr. Scott is the king of the maroons. Later, Flint tells his crew about Mr. Scott's idea, but first he must convince The Maroon Queen to agree to the plan. He tells them that if he feels The Maroon Queen will not agree to the idea, then he will take The Maroon Queen hostage and force her to release his crew. Flint is brought before The Maroon Queen and Dr. Howell shows Billy the knife Flint was supposed to use to take The Maroon Queen hostage left on the ground. Afterwards, Billy and the rest of the crew are freed by Kofi.
During the events of Black Sails: Season 3 Episode 7 XXV. played by Alistair Moulton Black
De Groot tells Flint that Nassau has been spotted. Silver goes to a tavern with Billy, Dooley and Joji. Once they are back on the ship word spreads among the crew that Silver killed Dufresne.