Grandpus gives a lesson to Fire, Simka, and Nolik at the warehouse. He teaches them to screw themselves into a wall in case of emergency breakdowns. Simka and Fire do the task with ease but Nolik is scared because once he had screwed himself into an appliance that was plugged in and got a terrible shock. Grandpus decides to be an example for Nolik and he screws into a shelving unit. Unfortunately, he is unable to unscrew himself without help. Professor Eugenius tries to help Grandpus but he loses his footing and falls down. Soon he is buried in boxes that have fallen on him and he can’t get up. The shelving unit tilts and a heavy electric motor is about to fall from the top shelf right on Professor Eugenius! The only thing that can save Eugenius is to securely screw the shelves into the wall. Simka and Fire quickly screw themselves into empty holes but it’s not enough to stabilize the unit. One more screw is needed! Nolik overcomes his fear, takes a daring leap and screws himself into an empty opening. Whew! The shelves are secured! But who is going to free Eugenius from under the boxes? The only hope is for him to wait for his assistant Elisa to return from her vacation later that day. Hope her plane lands on time!