Olive's Ocean by Kevin Henkes (Paperback)

Martha Boyle and Olive Barstow could have been friends, but they weren't. Weeks after a tragic accident, all that is left are eerie connections between the two girls, former classmates who both kept the same secret without knowing it.

Now, even while on vacation at the ocean, Martha can't stop thinking about Olive. Things only get more complicated when Martha begins to like Jimmy Manning, a neighbor boy she used to despise. What is going on? Can life for Martha be the same ever again?