You were chillin in the lair with the turtles. Leonardo was training, Donnetello was in his lab, working with some mutagen, Raphiel was feeding Chompy some fresh lettuce, and Michalangilo was skateboarding.. in the lair.. and before you knew it, he skated right into Donnie's lab, crashing into him, and sending the mutagen flying out of the lab and splattering all over you!