Maria Black, the woman''s school headmistress who doubles as a detective, is invited to attend the engagement celebrations of an ex-pupil of her college.

There she finds herself involved in the mysterious suicide of the prospective bridegroom, Keith Robinson. All the circumstances--death by hanging in a locked cellar--support the idea that Keith took his own life. The coroner, too, is satisfied that such was the case--but certain peculiar factors of the death lead "Black Maria" to think otherwise.

Aided by her American Bowery companion, "Pulp" Martin, Maria sets out to prove how Keith really died--and in doing so uncovers an ingenious plan of cold-blooded murder. But who is the killer--and why was Keith murdered? This fifth--and final--novel in the Black Maria series is a classic "locked-room" crime novel, one that will leave the reader guessing right up to the last page!