An Invisible Murder

When travelling cook Jenny Starling starts her new job at Avonsleigh Castle, she is thrilled. She envisions nothing more arduous than days spent preparing her beloved recipes. But when a fabulous bejewelled dagger, one of the castle's many art treasures, is used to murder a member of staff, the Lady of the House insists that Jenny help the police with their enquiries. But how was it done? The murder was committed in front of several impeccable witnesses, none of whom saw a thing. It seems the reluctant sleuth must once again discover the identity of the killer in their midst...
An Invisible Murder by Joyce Cato