Although it ends up being a rather middling melodrama, Sealed Cargo's first half is a fairly tight, involving little war-time thriller, one which benefits from its setting on the "home front." Without the battle-scarred background of Europe to deal with, director Alfred L. Werker is able to create tension in the possibility that the dreaded enemy is about to invade a small Newfoundland village, and he does an admirable job of slowly building the tension and of keeping the audience moving to the edge of its seat and then backing off, only to edge it back up again. Unfortunately, after a good start, the film devolves into a muddled mess; suspense is thrown away in favor of purported "action," but the action sequences aren't particularly involving or interesting. There also are some plot twist problems throughout; although these are kept to a minimum, they are noticed. In the lead role, Dana Andrews has some very good moments but also has several moments where he seems to just be walking through things. Carla Balenda is only acceptable, although her role is also poorly written. The best performance comes from the reliably sinister Claude Rains.