Carr clearly got a taste for murder as the series progressed, bumping off Paloma Faith in plain sight and handing Lucy Beaumont her death warrant.
But this time round, his conscience re-emerged, and he found it "heartbreaking".
"I'm really hoping third time's a charm," he said, trying to convince himself he still had it in him to keep going.
Host Claudia Winkleman was rattled by Imrie's murder, declaring: "I love her", as she stalked out of the breakfast room clutching her portrait.
Perhaps not surprisingly, Carr later looked a bit edgy about the upcoming round table, telling Cat Burns his Shakepearean moment was "so obvious".
"I'm so nervous, what do we do if everyone goes for me today," he said.
"I just hope no one puts two and two together with the the eggy Shakespeare quote."
Later on, the contestants had to put their doubts and suspicions aside for the day's challenge - in a creepy room full of headless dummies, which needed their Celebrity Traitor heads reattached.
Easy enough - except our celebrities had to navigate through a fiendish array of red laser beams, all pointing at awkward angles, meaning the most nimble had the easiest time of it.