Dead Man's Hand (Jake of Spades #4)

Barton Montoire, the ghost of a nineteenth century riverboat gambler, is devastated and angry. His lover, physics professor Sabine, has exorcised him. Again. This time, there's no denying the professor's actions were intentional. Worse, Bart can't seem to convince their friends to aid him in his quest get Sabine to listen to his side of things.  

With his lover Bart safe from shadowy threats of eternal damnation in the "other realm," ghost hunter Sabine Brusilov is free to pursue his own risky investigation into the mysterious circlet and its connection to the shadow figure that's been tormenting the unlikely couple. With the help of his friends, he determines to take control of the situation and bring Bart home.