Richard E Grant was banished from The Celebrity Traitors and Hannah Fry was recruited in his place during Thursday's episode.
The actor received the majority of votes from the other contestants, including from both of his fellow traitors, Maya Jama and James Acaster.
Grant's confession and banishment
As Grant stood in front of the players to reveal his identity, he said: "I am… an unfaithful traitor."
Speaking to the camera, he added: "I have been annihilated. I have managed to checkmate myself, which, as far as I'm aware, has never been done."
Hannah Fry recruited as traitor
Rather than murder, Jama and Acaster chose to seduce mathematician Fry and make her the third traitor.
The professor accepted their offer to join following the roundtable.
After seeing her fellow traitors for the first time, she said: "I was sure you were faithfuls, you absolute legends. Oh, it's going to be so fun!"
Challenge and roundtable drama
In the challenge, the players were tasked with breaking down the doors of four crypts with a large ram, with two chosen players entering to retrieve money or a shield, protecting them from murder.
Myha'la and Fry went into a crypt together and the actress got the shield for herself, but then felt bad because she thought the mathematician had more "heat" on her from the others.
Actress Sharon Rooney and Jama also found shields, but in the final crypt it was revealed two shields had to be sacrificed to get the prize money so Myha'la and Rooney gave theirs up.
The players won £6,000 in the challenge, bringing the total prize pot to £26,000.
At the roundtable, suspicion quickly fell on Myha'la, who said she would "fight to the death" to keep her place in the game.
Coronation Street actress Julie Hesmondhalgh thought that the actress had exchanged a suspicious look with Grant after his banishment while The Last Of Us star Bella Ramsey said they had suspected Myha'la all along.
Others suspected Jerry Hall, particularly comedian Joanne McNally and Little Mix star Leigh-Anne Pinnock, who said she caused "confusion" in the game.
Acaster tried to throw the faithfuls off by saying he thought actor Michael Sheen could be a traitor because he seemed like someone Grant might have recruited.
Ultimately, Myha'la received the majority of votes from her fellow celebrities and was banished from the castle.
In her speech, she said: "I have loved getting to know you all, thank you for loving me. I will say to the faithfuls, I don't think the traitors are as dumb or silly or confused as you might think they are. I think they are a lot smarter. But I have been a faithful. Love you."
Cliffhanger ending and viewing figures
After the vote, several players began to throw names around as suspicions rose.
James Blunt said he suspected Hesmondhalgh, Ramsey and EastEnders star Ross Kemp, while Miranda Hart had her eye on Fry.
The show ended on a cliffhanger as Fry, Acaster and Jama deliberated over who to murder in the turret.
Acaster suggested they murder Blunt because it would be a "chaotic" move that would confuse the other players.
Fry felt actor Sebastian Croft would make a better victim while Jama thought Ramsey should go because they were "the only person smart enough to kill all of us".
The episode ended before viewers could find out who was murdered.
The first episode was the most watched debut of any series of the programme in the UK when it aired last week, with an average audience of 8.9 million viewers, peaking at 9.1 million at one point.
In the hit series, hosted by Claudia Winkleman, 21 celebrity contestants take part, with those assigned as faithfuls attempting to seek out those who have been made traitors, who "kill off" players in the middle of the night.
The celebrities are playing the game at Ardross Castle in the Highlands, with a cash prize of up to £100,000 for a charity of their choice up for grabs.
