Blue as Blue Jeans - Biscuit McKee Mysteries Revised edition

Sam returns to Martinsville after an absence of several decades, just in time for the annual Halloween celebration at the town library. Biscuit, the town librarian, is the only one who's not in on the joke as long-time residents recall some of Sam's antics as a kid-antics apparently shared with Biscuit's relatively new husband Bob.

When a grisly murder is discovered the next day, with a body tangled in the storm wreckage of the town dock, Bob and Biscuit-and of course Biscuit's cat Marmalade-are caught up in the repercussions of long ago events that came to call that stormy Halloween night.