Captain John Winslow (Arthur Byron) is notified by the Secretary of the Navy that his cruiser will be receiving a new firing control gear manufactured by World Electric company, which is supposed to revolutionize naval warfare.

When the gear is returned to the ship the secrecy surrounding the events catches the notice of reporter Walter Drake (J. Anthony Hughes).

Lieutenant Tom Randolph (Robert Taylor) and Captain Winslow welcome visitors Al Duval (Raymond Hatton), who works for World Electric Company, and Victor Hanson (Jean Hersholt) from the Navy Department, aboard while the gear is installed.

Meanwhile, Sailor Spud Burke (Nat Pendleton) gets caught between his sweetheart Toots Timmons (Una Merkel) and an old flame Betty Lansing (Jean Parker).

The Captain devises a plot to trap the murderer and the trail soon leads to the powder magazine, where Victor Hanson threatens to blow up the ship.