The Paranormal Investigators League is dedicated to investigating and dealing with paranormal phenomena. They hear of an incident in Tucson, Arizona, involving the shadowy figure of a cowboy that seems to be attached to a small boy. Because the boy's father is afraid that the figure might be dangerous--it is certainly creepy--he asks the P.I.L. to investigate. Sure enough the Shadow Man turns out to be the ghost of a bank robber hanged in the 1850s haunting the former saloon, now turned restaurant, he used to frequent when he was alive. The Investigators are able to confirm that the ghost is causing various events to happen in the restaurant that at first seem benign but become more and more harmful as time passes.

The ghost has a temper and is growing stronger as time passes. It turns out the ghost is developing its strength because he is an ancestor of the man who now owns the restaurant. The P.I.L. has to find a way for the ghost to communicate with his descendents before disaster overtakes them all. A Hanging in Tucson describes the investigation and the methods the Investigators use to make sure everyone, ghost and living people, have a happy ending.