Wish Upon a Star by Michelle McLean
Ceri McKinley never stopped wishing that her ex-fiancé Jason Crickett would come back into her life. But when he finally does, he comes with a request that puts them both—and all of humanity—into jeopardy.
Jason only wants two things: to bury his brother properly and to convince Ceri to trust him again after he jilted her. But when Ceri agrees to help him get his brother back, they end up fighting for their lives as the second zombie uprising threatens them all.