In That Sinking Feeling, Ronnie convinces his friends to go along with his plan. They begin to gather supplies and costumes and practice their feminine walks. However, they soon realize that their plan is not foolproof and they need to come up with a new approach.
Ronnie then discovers an unusual potion called "stop-motion," which can freeze the movements of whoever drinks it. They come up with a new scheme to use the potion to immobilize the warehouse guards so they can steal the sinks.
After successfully stealing the sinks, the boys plan to sell them for a lot of money. However, their plan begins to unravel when one of the sinks accidentally falls into a canal, and they are forced to spend a lot more money than they anticipated to save it.
As they try to sell the stolen goods and make their money back, they run into various complications, including a suspicious police officer and a group of thieves who want to steal the stolen sinks from them.
The film is a dark comedy that highlights the struggles of unemployment and poverty, while also showcasing the creative and unconventional methods people use to survive.