Time is running out for Karl as Michie has already filmed his final scenes in the role and is expected to bow out on screen in September.
Karl is still hiding the fact that he started the Rovers Return fire and killed Sunita Alahan. However, his final weeks on screen will see him find it extremely difficult to continue keeping the truth under wraps.
Michie told TV Times: "It's quite short and intense - a month of Karl ducking and diving, trying not to get caught.
"I think the writers have got his exit just right. He doesn't die, which is good. You never know, in a couple of years he might come back. I don't believe in closing any doors."
The main problem for Karl will come in the form of schoolboy Craig Tinker (Colson Smith), who knows more about the pub blaze than anyone thought.
Michie explained: "Karl was starting to think he'd got away with it, until Craig comes up with this annoying fact which plunges him straight back into the jungle of madness. He feels he can control this kid, at least for a period of time.
"Karl will do anything to get his prize, which is Stella, so Craig had better watch out. I know I've always said that Karl is no killer, but he's starting to go slightly mad now."
Michie already has his next project lined up as he has joined the cast of BBC One's Holby City.
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