Complex sentence: He then traps Marv stuck under the dumbwaiter and unleashing his traps on Marv and Vera, then Molly appears, Kevin then traps her in the elevator and runs to his bedroom.
Split into simpler sentences: He then traps Marv under the dumbwaiter and unleashes his traps on Marv and Vera. Kevin manages to trap her in the elevator and runs to his bedroom.