When Mary's son Zack brings an antique guitar to Sparrow Island, its mysterious history sets off a search for a musical legend--and a rare colony of bats. A student whose life was changed by Abby's mistake years ago joins in the search, but will old wounds distance them once again? Meanwhile, Mary discovers her deceased husband's unpublished manuscript and unearths long-buried family secrets. As Abby searches for the bats and struggles to untangle the history of the famous instrument, she also learns that forgiveness and love can heal even the deepest of rifts.