Relief Valve by J. L. Merrow

If you dig up the past, be prepared for some dirt to stick.

The relationship between Tom Paretski, a cheeky plumber with a gift for finding hidden things, and PI Phil Morrison may only be a few weeks old, but already it's under attack. Tom's friends and family are convinced the former bully isn't good enough for him, and they're not shy about saying so.

Then Tom's prickly older sister, Cherry, is poisoned at her own engagement party. Tom's left reeling and not knowing who to suspect. Could it be her new fiance, Gregory, a cathedral canon with an unfortunate manner and a taste for taxidermy? Or someone from her old writers' circle, which she left after a row? Or could the attack be connected to her work as a barrister? Meanwhile, Tom's honorary auntie's left him a gag gift from beyond the grave that could be more significant than anyone knows.

Phil's fighting against the clock to solve the case before somebody ends up dead. And with the poisoner hiding a dark secret, Phil's terrified Tom could have been the target all along.

This book is part of the "The Plumber's Mate Mysteries" series.
Here are some other books from this series: