Traitors

In Daydream Software's Traitors Gate, you play Raven, an operative for an organization called ORPHIA. Your employer suspects that one of its high-ranking operatives is planning to break into the Tower of London to steal the crown jewels and has hired you to commit the crime before he can. Your task: to sneak in, steal the jewels, replace them with replicas, remove all traces that you were there, and then get out.
Even so, it's good fun once it's actually working. Traitors Gate is admirable for being both logical and nonlinear. The latter is especially noteworthy - you could easily play through the game several times and take a different route each time, at least until the somewhat linear endgame. And if you don't mind the unrewarding ending, you'll most likely want to play it more than once just to see all of the locations you missed the first time. Traitors Gate isn't an excellent game, but it's very good.

Hitler's British Traitors is the first authoritative account of a well-kept secret: the British Fifth Column and its activities during the Second World War.