Rescued by a passerby, Chief Petty Officer Ichabod Ferdinand “Fixit” Smith, Houston tells him that his name is Jim “Tennessee” Jones; when he gets off at the next town, he wants to send a telegram, he looks at a newspaper cutting he keeps - a picture of himself with the headline reading ‘Naval Officer Missing- Lieutenant Richard Houston Sought by Naval Authorities.’ He crumples the paper, and proceeds to write a telegram to the Records Office at Arkansas, requesting the birth certificate of one James Smith born in 1909. (The good Samaritan who rescued him had mentioned that his name Jim “Tennessee” Jones sounded familiar, he knew someone born in 1909 by that name, a distant cousin- this gives Houston the chance to further strengthen his fake identity).
The man takes him home, where he meets Mary Smith, ‘Fixit’ Smith’s niece, who lives with him and Mom Smith. Jim enlists in the Navy, he makes careful efforts to remain unnoticed, purposely missing targets in at the rifle range etc. but in spite of this, before long, is promoted to the rank of Gunner’s Mate.
He vies for Mary’s affection, pitted against Elliot Nash (Russell Hayden), whom he meets on Mary’s birthday - in fact both men end up gifting her the same vanity set, except that the one Jim gave her has a note that reads “Happy Birthday to Blue Eyes”. The three men are assigned to a mine disposal ship, one day, they are on a scouting mission, when the mooring’s of the vessel are trapped in a landmine. Teaming up with two other sailors, Jim and Elliot examine the problem at hand; the former dislodges a knife from the mine, and they return to the ship, wondering about how the bomb looked a lot different from other they’d seen. Unfortunately, as soon as they return, the two sailors are killed in the mine blast.
Lieutenant Gilpin (Frank Felton, Gun Man Down) is allocated the task of training both Gun Mates in the field of diffusing mines underwater; on their first assignment, Jim’s oxygen lines become tangled in a net - Elliot saves his life. When Lt. Gilpin sifts through Jim’s belongings, he comes across a pocket watch with the name Richard Houston engraved on it - this gives rise to suspicion, and the Lt. unbeknownst to Jim, starts to investigate his true identity. He finds a write-up and photograph of his in a Naval record book - he writes to the US Naval Academy from where Houston graduated , to furnish personal details of the man, including his current whereabouts - stating at the end – ‘this is strictly unofficial.’
Meanwhile, Jim is so besotted with Mary and determined to win her hand, that he “borrows” ten bucks from a colleague and wagers it in the hope that he may use the winnings to buy an engagement ring - he loses the money as well as misses out on a dinner date with Mary. Fixit makes the needful excuses on Jim’s behalf, and is then sent on duty. Sadly, a Japanese mine is set off and Fixit dies in the mishap. Meanwhile, Jim returns and proposes to Mary, who seems sad and preoccupied, when she asks Jim whether he’s heard anything about her Uncle, he replies he isn’t aware - and is shocked to learn of his kind friend’s sudden death.
Bewildered and contrite, he tells Mary the truth about his own identity and plans to run away again. However, he receives orders to return to Base, where Lt. Gilpin wants to unearth how the mines work - he orders Jim to dive and find out. When Elliot and Jim dives, they discover that the mines are sensitive to sound, and are propelled by sound waves. Jim compels his friend Elliot to move up to the surface, as he tries to disable the mine - suddenly, the mine explodes and Jim is killed. Lt. Gilpin was able to unearth and dismantle countless mines based on the information Jim shared before his death, for which he is awarded the Navy Cross posthumously.