Have you met my ghoulfriend? - R.L. Stine

Master horror writer and Goosebumps series author, R.L. Stine, delivers another spooky tale!

Nicky and Tara still live in Max's bedroom, and while they've found some clues, they
still don't know what happened to their parents. Meanwhile, Phears is still desperate
to get his hands on Nicky and Tara, and to pressure Max into turning them over, Phears
brings a Berserker Ghoul to inhabit Max's body-and make Max go berserk when he least
expects it! But Max, Nicky, and Tara aren't giving in to Phears. They have a few
tricks up their sleeve-like one very talkative ghost cat, who's taken residence inside
the tunnel to the ghost world. . . .