Building a Building.

Mickey's a shovel operator and laborer at a construction site; Minnie is delivering box lunches; Pete is the foreman. Mickey pays more attention to Minnie than to his work, and keeps having accidents (mostly involving the blueprints Pete is holding). Pete steals Mickey's lunch, so Minnie offers him one on the house. While he's eating, Pete kidnaps Minnie; Mickey fights him, but the tide turns when Minnie dumps a load of hot rivets into Pete's pants...