A chimp in a spaceship goes off course into the far edges of the universe. Aliens enhance his intelligence to make him Captain Simian, so he can defeat the evil Nebula, who wants to take over the universe.
The crew find a derelict ship, some crystals and an alien egg. The egg hatches with a quick-evolving alien that threatens the ship and crew. Splitzy uses the crystals to trap the alien and dump it into space.
The crew encounter an idyllic-looking, Earth-like planet run by a protege of Nebula, Rhesus 2, who has actually enslaved the planet. Captain Simian and his crew has to free them.
An unknown ship attacks the Avenger crew, kidnapping Gor and Spydor, who are forced into a fight ring. The Simians find them just in time to rescue them.
Giant alien bananas attach to the ship, capturing some of the crew and making clones of them that take over the ship. The captain has to find the home origins of the bananas in order to free his crew and ship.
Rhesus 2 steals gravitons that cause a rip in the fabric of the universe. Charlie helps an alien put the gravitons back to seal the rip and save the alien's world.
The Simians ride a meteor through a wormhole, finding an alien planet on the other side that the meteor is about to hit. They try to warn the inhabitants but can't communicate, so they have to save the alien planet themselves.