Mystery Magnet by Gregory Ashe

He was born to write mysteries. Now, he has to solve them.
When Dashiell Dawson Dane moves across the country to a small seaside town called Hastings Rock, he has one goal: get away from his ex. Okay, two goals - because he wouldn't mind a little help from his new boss, celebrity mystery author Vivienne Carver. With Vivienne's mentorship, Dash is sure he can get over this blasted case of writer's block and start telling his own stories again.
The only problem? Vivienne is murdered on Dash's first night at Hemlock House. And when police find a secret passage that connects Dash's bedroom to Vivienne's, they're sure they know who did it. Now Dash has to prove his innocence - and the only way to do that is to figure out who really killed Vivienne Carver.