Murder at Hazelmoor

I bought most of my Agatha Christies in the early 80s, some of them new and some used.  Murder at Hazelmoor fooled me - the spine is uncracked and it has early-80s cover art, but there's a stamp from The Book Swap on the inside cover.  It's also spent over 30 years on my shelf, unread - maybe I was more likely to file away the books I bought used.  In this case, I didn't miss much.  Murder at Hazelmoor is a middling locked-room Christie - a seance proclaims Captain Trevelyan's death and a few hours later, when Major Burnaby checks on is friend, Captain Trevelyan is dead.  The police settle on Trevelyan's nephew as the most likely culprit, and the young man's fiancée sets out to prove them wrong.  Cleverly plotted and diverting, but not particularly engrossing, it's a casual Christie - worth reading, but maybe not worth hunting for.