Karl steals Jason's work van, drives it to a remote spot and torches it in March 8's double bill of the soap.
The desperate act comes as Karl aims to cause as much trouble as possible for Jason (Ryan Thomas) now that the builder is dating his ex-partner Stella Price (Michelle Collins).
Tempers boil over when Jason later figures out that Karl was responsible for the van incident. However, when Stella refuses to believe this theory, it seems that Karl's plan might be working.
John Michie, who plays Karl, told itv.com: "It's not just about getting revenge or getting his own back. Jason's a builder, so without a van he won't be able to do a great deal. He wants Jason to fail as the boyfriend, so it's vindictive and nasty - there's a definite plan.
"He certainly thinks he has done a good job. He's quite proud of his plan and how he took the van, where he blew it up and that nobody saw anything. He got a bit of a thrill out of that sort of devious behaviour."
Michie added that he is delighted to be exploring a darker side to Karl in his current storyline.
He said: "It's always interesting to play the bad guy. He's essentially not evil, he just gets caught up in situations and events certainly take over, then he has to deal with the consequences.
"Initially he has a plan and a calculation, but it all goes horribly wrong, and then he has to catch up with the events. It's the events themselves that turn him bad - deep down he himself isn't a bad person, he's just obsessed and in love. The best thing for Karl would be to leave Stella alone and not be with her."
Coronation Street continues tonight (February 25) at 7.30pm and 8.30pm on ITV.
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