When Mason Stark's classmates start to disappear mysteriously and he discovers an ancient, powerful enemy, he calls on his friends--both human and Tremist--to fight as he once again must act as an intergalactic hero.

Captain Raptor and his spaceship crew rush to investigate when an unidentified object lands on one of the moons of the planet Jurassica.

As her dad and best friend lie dying in the hospital, Miki and Jackson prepare for the final mission that, hopefully, will win the Game before the walls between the real world and the deadly Game come crashing down.

Seven-year-olds Bradley, Brian, Nate, and Lucy make observations and gather clues that convince them that their older siblings, cousin, and animals have been captured by hungry space aliens.

Traveling to Cleanix to investigate why floating space junk has engulfed MouseStar 1, Geronimo finds that the planet's alien inhabitants are extremely wasteful and face the threat of rebellion by the robots they've thrown in the trash.

Twelve-year-old Gabby is recruited by a secret agency to take care of extraterrestrial children.

In the near future, four teenagers discover that their emotions have been weaponized and that they have been genetically bred to end the alien occupation of Earth.

The enemy is Other. The enemy is us. They’re down here, they’re up there, they’re nowhere. They want the Earth, they want us to have it. They came to wipe us out, they came to save us. But beneath these riddles lies one truth: Cassie has been betrayed. So has Ringer. Zombie. Nugget. And all 7.5 billion people who used to live on our planet. Betrayed first by the Others, and now by ourselves. In these last days, Earth’s remaining survivors...

Nicola and her Space Brigade friends go on a mission to save the planet Shobble from a sinister plot that threatens all but an elite few of its citizens.

Resenting his Animorph powers, Marco prefers to watch over his widower father until he learns that his mother is still alive, and he is horrified to discover that she is the highest ranking officer in the Yeerk army.