Alfred Hitchcok is not my favorite director by any means but imagine what he could have done with this! The plot holds much potential for suspense. John Garfield is as almost always excellent and Raymond Massey is scarily cast against type. Nancy Coleman is not a very impressive leading lady but the supporting cast is large and very capable.
Yes it starts to sag fairly early. There are too many coincidences. And an important subject is trivialized by its being made into little more, in the end, than a love story.
It's fun to watch for Garfield, Massey, and the character performers. But it's not awfully good.