When Gabriel Dubois, Lordsburg's town drunk, dies of a heart attack in the middle of the street after being harassed and humiliated by four ranch hands, his death inadvertently opens a can of worms. Sheriff William Riley and Doctor Brent Ellison discover that Gilbert had no personal possessions in his room at Ma Baker's Boarding House, other than a tin box with two letters inside. Dubois had lived in the boardinghouse from 1892-1902 and worked as an assistant to the blacksmith. When they approach Ma Baker for an explanation, she has nothing to tell them.

Skeptical, Doc Ellison reviews his records. There have been a number of deaths at Ma Baker's: six young men over a six-year period, all allegedly dying in their sleep. Both the doctor and the Sheriff believe they were poisoned and their possessions stolen then sold by Ma Baker. They speak to Mortimer Trask, the town's mortician, and he agrees to exhume the body of one of the victims who had no family or heirs. The local chemist agrees to sample the bones and tissue remaining and determine if the man died of Wolfsbane poisoning—a plant the Doctor and Sheriff found in the backyard of the boardinghouse. The chemist confirms poison and, armed with a search warrant, they uncover a tincture hidden in the kitchen's spice cabinet.

During the search Sheriff Riley and Doc Ellison discover more evidence which leads to the arrest of Ma Baker. She denies the charges, but when the case is picked up by various newspapers across the United States, several men come forward, claiming to be survivors of her poisonous treachery more than fifteen years ago. Before buying the boardinghouse in 1890, Mira Norwood had been widowed twice, both husbands dying in their sleep before their first anniversaries. Mira was their sole beneficiary.

Her trial in the territorial court before three judges is scheduled for September 16, 1902 in Silver City, New Mexico, with the Sheriff and Doc Ellison as witnesses. Ma Baker, now revealed to be Mira Norwood Penny Thompkins has hired an attorney, Aurelio Perillo, whom Steve Dillon, the territorial prosecutor, thinks is a hack. As the trial enters its second day, a shocking revelation brings the proceedings to an abrupt halt. With the prospect of a new trial looming, Steve Dillon suggests Mira Norwood be sentenced to thirty-five years in prison without parole. Will the judges accept his recommendation? And if they do, will Mira agree to spend more than three decades in a new territorial prison for women in Yuma, Arizona?

Follow the investigation as the doctor, Sheriff, mortician and the prosecutor work together to seek justice for the young victims and their families.