S1·E37 Kilokahn Is Coming to Town

A power surge in syberspace sends Sam into an alternate universe, where everyone he knows is way different than from the universe he knows - for example, Yolanda is evil and creates viruses for Kilokahn, and Malcolm is a good-spirted guy who likes to help people. Sam must destroy the Hockinator virus in the alternate universe and find a way back home before it's too late.