There is a strange planet appearing and disappearing from the radar on MouseStar 1! Geronimo and the crew land on the mysterious planet to investigate. When they arrive, they discover the aliens who live there are hiding a secret. Can the crew solve the mystery and save the planet before it's too late? ...

Great Gouda! Tony Sludge and the Sewer Rats have turned day into night, and they want the sun to stay away forever! Now it's up to the Heromice and the myterious new crime fighter Super Eto stop them. But can Superstilton and his friends bring daylight back to Muskrat City before it's too late? ...

Super Swiss slices! Tony Sludge and the Sewer Rats have invented a new device - a shrink ray that can turn things tiny! Tony has a plan to use it to steal all of Muskrat City's gold. It's up to the Heromice to stop him, but they'd better be careful the Sewer Rats don't turn them into mini-mice first! ...

Professor Greenfur, MouseStar 1's onboard scientist, has changed color from green to... orange! What's going on? To uncover what's wrong, the spacemice travel to his home planet of Photosyntheson. Professor Greenfur's relative are being threatened by the nibblix, tiny aliens with very sharp teeth! Can the spacemice help in time? ...