Synopsis by Hans J. Wollstein
In the opening chapter of Republic's S.O.S. Coast Guard, Officer Terry Kent (Ralph Byrd) is assigned by Commander Boyle (Herbert Rawlinson) to rescue a cargo vessel in distress. One of the survivors, however, is recognized as the infamous bearded inventor Boroff (Bela Lugosi), but before Terry can react, the villain has disappeared into the fog. Jim (Thomas Carr), Terry's brother, takes up the chase but is brutally killed by Boroff, who then has his mute sycophant, Thorg (Richard Alexander), remove the telltale beard. Alerted to the fact that something is amiss on the stranded S.S. Carfax, Terry, his reporter girlfriend, Jean Norman (Maxine Doyle), and her flibbertigibbet photographer, Snapper McGee (Lee Ford), board the wounded vessel but run afoul of Thorg, who is cutting the mooring cables in order to destroy all evidence of Boroff's contraband, a powerful disintegrating gas that the villain has been peddling to an enemy power. Trapped in the hull, the coast guardsman and his friends can only watch in horror as the ship sinks.