Annie Leblanc is not dead yet / Molly Morris.

Enhanced descriptions from Syndetics:

Every ten years in the strange little town of Lennon, California, one person is chosen to return from the dead...

Wilson Moss entered the town's top-secret contest in the hopes of resurrecting her ex-best friend Annie LeBlanc, but that doesn't mean she thought she'd actually win. Now Annie's back and Wil's ecstatic--does it even really matter that Annie ghosted her a year before she died...?

But like any contest, there are rules, and the town's resurrected dead can only return for thirty days. When Wil discovers a loophole that means Annie might be able to stay for good, she's desperate to keep her alive. The potential key? Their third best friend, Ryan. Forget the fact that Ryan openly hates them both, or that she and Wilson have barely spoken since that awkward time they kissed. Wil can put it aside for one month; she just needs to stop thinking about it first.

Because Wil has one summer to permanently put an end to her loneliness--it's that, or lose her only friends...again. But along the way, she might have to face some difficult truths about Annie's past and their friendship that, so far, she's left buried.