This was Sally Gray's last film in which she appeared in an evolving romantic role alongside George Raft.
Quite why the actress should have agreed to this one is something of a puzzle. Admittedly she had already done some "thrillers" (for want of a better word) but an espionage? Why not? For me, I like to identify the characters with the roles they are expected to portray, but the problem with spy stories is that one is never quite sure where the individual's true loyalties (if they have any) lie.
In Escape Route we have a high level of serious content. It takes a little time to sort out who are the good folk and who may be the not so good. Sally is shown to be quick on her feet and well groomed at handling herself against potential attackers (note that smart arm lock administered to Raft early on in the film).
The story amounts to an attempt to locate a certain Soviet guy named Michael Grand (Clifford Evans) and who eventually has to flee the UK (specifically London where the film is set - some interesting WW2 bomb sites included), hence the "escape" bit of the title.
As to the route taken; well this is the only funny part of the thing really for we are led to Mr Grand (in a grand, if rather tedious style) in the final stages through a series of chalk marks scratched here and there by Raft as he pursues Evans. (Look to when a stick of classroom chalk is handed to the chaser - real high-tech stuff - hilarious!). The final scene, too, has its ups and downs!
Harmless enough, if spying can be looked upon in that light, but not the best film to represent such a talented, beautiful lady as Constance Vera Browne, Baroness Oranmore and Browne (Sally Gray).