Andersson's Boatyard has done good business with Italy. However, when the money for the completed work is to be paid, trouble arises; the Mafia interferes with the shipyard owner and his daughter Petra. No money is paid out!

Andersson and Petra must scramble to raise funds for the bailiff, Peter Black, who is wildly pursuing Andersson. Black himself is also being hunted due to his own gambling debts. Meanwhile, the "Canoeist" has picked up a trail regarding the secret of the Canal King, Balzar von Platen. As usual, boats sink, things explode, and occasionally the boats are driven right up onto the land.

A cast of familiar faces and the tough, combative Boxer dogs, Debet and Kredit, appear in this third installment of Göta Kanal.

Related: Göta Kanal 2