Dana Andrews is police detective Mark Dixon, whose deep hatred of all criminals has lead him to treat gangsters with extreme prejudice to the point of being officially brought up on departmental charges of abuse. He has built his career as a cop because his father had been a criminal, something that has scarred Dixon psychologically. When the cops break up a floating crap game at the apartment of Tommy Scalise (Gary Merrill), and discover a dead body, they send out the alert for grafter/ gambler Ken Paine (Craig Stevens) as a murder suspect. Dixon tracks down Paine and tries to convince him to put the blame on Scalise, but during his rough questioning, accidentally kills him. In disposing of the body, Dixon narrowly avoids being caught by cab diver Jiggs Taylor (Tom Tully), who coincidentally happens to be the father of Morgan (Gene Tierney). Though circumstantial evidence, the police place the murder of Paine on Jiggs. Morgan is married to Paine and although separated, the gambler utilized his attractive wife to lure victims into gambling games. Dixon tries to clear Jiggs without implicating himself but cannot establish the cab driver's innocence without confessing of the murder of Paine himself. Morgan and Dixon have fallen in love and she stands by him even without knowing the full story. Dixon sees no alternative except to confront Scalise alone without assistance, and the result is a revealing moment to both Dixon and the criminal.