Survival — K.A. Applegate

The best-selling author of ANIMORPHS and EVERWORLD presents a fresh, exciting, and gritty science-fiction series that combines a little 2001, a little Armageddon, and a whole lot of action!

Tate is fighting for her life. Honey, Duncan and Charlie are mysteriously transforming into slime creatures and they are desperate to "recycle" all of the living cells -- into their own bodies.
But Tate has something Honey wants even more than cells. She'll manage to save her life by forging a strange alliance with these creatures.
Tate is haunted by a strange reoccurring dream of the renewed Earth. Do the dreams mean Tate can use the powerful ship to undo the devastation caused by the Rock?