Lew Weldon has been a tumbleweed, rolling where the wind blew him, up to Canada and down to Mexico. Over time he has earned a reputation as a gambler and a gunfighter. Riding into San Trinidad, Weldon finds his reputation has preceded him when he receives two job offers. Roger Cunningham wants Lew to join his smuggling operation. Dr. Henry Watts wants to hire Lew to protect his patient dying of consumption, the beautiful Helen O'Mallock. Lew finds Watt's proposition far more attractive, so he accepts the offer, knowing that Cunningham will resent the decision. Helen's father, General O'Mallock, had hidden a fortune in the house before his death. Helen lives there alone with only a few servants. Her house has already been entered twice by strange men, and an attempt has been made to poison Helen, as if her physical impairment is taking too long to kill her. Dr. Watts is convinced that the potential thieves want Helen frightened into leaving the house, if not put directly out of the way, so they can conduct their search at leisure. If she can be made to leave, her life might be spared. After investigating the O'Mallock house at night, Lew Weldon realizes he is not only up against incredible odds, but that in this matter no one is to be trusted.