A lesson in secrets : a Maisie Dobbs novel by Jacqueline Winspear.

In the previous books of the series, Jacqueline Winspear wrote about such issues as class, mental illness, returning veterans, and continuing tensions between nations in the aftermath of World War I.  Now Winspear takes up the rise of the Secret Service.  Maisie Dobbs has just been asked by the Special Branch of Scotland Yard to get a job as a lecturer at a newly founded pacifist university.  Maisie's assignment is to discover who is sympathetic to the rising Nazi party and what they are doing in support of the party.  Almost before she begins, the founder and president of the college dies from an apparent heart attack. Maisie quickly determines that the president was murdered and uses her undercover identity to try to find the killer.  Another engrossing look at post World War I England! 323 pages.