Planet Z (Planet Z Book 1)

Jill and Carlos are twins leading a blissful family life. They are suddenly cast into deepest despair upon losing their loving mother in a horrific automobile accident. It's their brilliant father that takes it the hardest and in an attempt to somehow contact his wife in the afterlife, he unwittingly transports his children there. They now have to survive on a planet acting as a way station for all of Earth's departed and are suddenly embroiled in a plan to allow the dead access back to their home planet. Not only do they have to find a way back, but they also have to stop a madman from bringing about the Zombie Apocalypse.

In Planet Z Book 2, Jill and Carlos have already lost all memory of their adventures on Planet Eve, but somehow the evil mastermind from that dimension has made it to Earth. Soon their paths will converge once more. Can Earth really be saved?