Gladys Mitchell:
Novels Under the Pseudonym "Malcolm Torrie"
In the 1960's, Miss Mitchell began a new series of books using the pseudonym "Malcolm Torrie."  These books were mysteries that featured a new amateur sleuth.  The recurring character Timothy Herring, a Secretary for a society that preserves historical buildings is joined in the third novel by the character Alison Pallis.  Miss Pallis is a history teacher and soon she and Mr. Herring become a husband and wife detective team.  Critics have written that the Torrie novels are very similar in character to the Mrs. Bradley series novels. 
Malcolm Torrie - A Chronology
Heavy as Lead - 1966

Late and Cold - 1967

Your Secret Friend - 1968

Churchyard Salad - 1969

Shades of Darkness - 1970

Bismarck Herrings - 1971