Tex, a famous detective, recounts the story of how he went into the crime business: While visiting his old friend, Jack Nelson, a dispute breaks out between Nelson and his butler. Later that night, Nelson is murdered, and the next morning the murder weapon, a knife, is discovered next to the body. Edna, the victim's wife, seizes the knife, and Tex, fearing that she is about to kill herself, throws the weapon out the window. Interpreting Tex's actions as incriminating, the police arrest him, and he is sentenced to prison. Two years later, a fire breaks out at the penitentiary, and Tex's bravery in saving the warden's wife and child wins him a pardon. Determining to solve Nelson's murder, Tex searches for the butler but discovers him to be innocent. Summoned to Edna's deathbed, Tex hears her confess to the crime, thus causing him to devote his life to solving crimes and saving innocents from being convicted on circumstantial evidence.