Girts and his friend are planning a trip to a mythical place - abandoned potassium park to try out some new drugs. In order to borrow the family car, Girts lies that they will go fishing. Parents agree on the condition he takes his younger brother along. The friend deceives Girts and has no choice but to really go fishing with his brother. Disappointed, Girts is nasty and impatient, but when his younger brother catches the fish it starts to think that he’s been unfair. As a gift to the youngest brother Girts shows him a secret entrance to the restricted territory of Potassium Park. They start exciting and dangerous exploration of the abandoned buildings until the younger brother finds a box with explosives that becomes a new challenge for their relationship.