The government believes there's something shady happening at a shipyard preparing to build an aircraft carrier, so they recruit “Gallagher” (Pat O’Brien) – along with a fabricated family – to go undercover. He recently worked overseas; his "wife" is FBI agent “Jill” (Carole Landis), and their children are presented as relocated refugees. Gallagher's estranged brother, “Jeff” (Chester Morris), who secured him the position, isn’t entirely sold on this setup. Jeff’s doubts heighten the suspense because he worries that his brother might be trying to reignite a past relationship with Gallagher’s girlfriend, “Lea” (Ruth Warrick), which only makes an already fragile situation even more difficult. The shipyard itself is inherently risky, so “Gallagher” understands that one misstep could expose him and put him in serious danger. Will he uncover the culprits before it's too late? Chester Morris has very little screen time, leaving the show largely to O’Brien, who manages to maintain the mystery’s momentum despite an abundance of dialogue at the cost of action sequences. I generally dislike romantic subplots in thrillers, but here, they also serve to emphasize that the fight against these Nazis is about protecting families. The final ten minutes are quite good, with some shadowy fights, and it includes the standard wartime public service announcement reminding viewers to be observant and discreet. It’s not a standout film, but it's an agreeable way to spend some time.

Source on TMDB