Sprouting a tail and spikes over the summer before fifth grade, Sawyer, a boy with the dinosaur gene, is bullied in school, but when his tormentors begin to disappear, it is up to Sawyer, his best friend Elliot, and a mysterious new girl to rescue them from a galactically horrible fate.

When the Animorphs try to stop the tiny alien Helmacrons from taking the morphing cube, Marco gets in the way and ends up with Helmacrons up his nose and inside his head.

The first day of seventh grade was probably the worst day of Duncan Dougal's life. He knows that things are really bad when he finds an alien's hand in a dumpster and then gets plugged into an alien brain fryer.

George is heartbroken when his neighbor Annie and her space-scientist father move to Florida, but when Annie sends him a secret message telling him she has been contacted by aliens with a terrible warning, he joins her in a galaxy-wide search for answers. Includes scientific essays on space travel.

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

"When Sky Patel-Baum is sent to live with her mysterious uncle, she didn't imagine she'd end up here: Area 51--a top-secret military base with a bajillion rules and so classified not even the president knows its secrets. Also, it turns out the place is full of aliens--lots and lots of aliens. But they prefer to be called Break Throughs, thank you very much. As Sky sets out to explore her extraordinary new home with her pizza-obsessed pet hedgehog...

When Amelia's parents decide to reopen a creepy old hotel, Amelia and her new friend Charlie quickly discover that the place is much more than it seems. The Gateway is no ordinary hotel - and its guests aren't just visiting from other cities and towns!

When almost-sixth-grader Alex, a video game fanatic, is forced on a "playdate" with his neighbor Herbert, an inventor, the two travel to the twenty-second century and face off against aliens, who are not as benevolent as most people think.

Space mouse Geronimo Stiltonix must replace the batteries in his damaged spaceship by tracking down a rare element, but he is wary of a group of mysterious aliens who offer their help.

MouseStar 1 is surrounded by floating space junk! It's yucky -- and dangerous. It's coming from a nearby planet, Cleanix. Geronimo Stiltonix goes to visit, and discovers that the aliens there are very wasteful. Even worse, robots that they've thrown in the trash have started to rebel! Can the spacemice restore harmony before the robots take over?