Professor Archibald Chagrijn exposes the world to his blubbering gas, which makes people sad and causes them to cry. Bassie proves immune to the blubbering gas -- as he has had an overdose of laughing gas. The professor is hiding on the Canary Islands, but Bassie and Adriaan manage to track him down.
Dolphin boy now has an important task. He is the guardian of the sea and must protect the sea creatures. In the meantime, the danger from the sea has not been resolved yet because the evil octopus, which is trapped in a hole, is designing and implementing new plans against sea creatures with the help of Shami. The boy must gather his intelligence and senses to take care of this boundless blue with the help of other sea creatures.