Ghost of a Dream — Simon R. Green

Meet the Carnacki Institute's operatives -- JC Chance: the team leader, brave, charming, and almost unbearably arrogant; Melody Chambers: the science geek who keeps the antisupernatural equipment running; and Happy Jack Palmer: the terminally gloomy telepath. Their mission: Do Something About Ghosts. Lay them to rest, send them packing, or just kick their nasty ectoplasmic arses…

The Ghost Finders are investigating a haunting at the long-abandoned Haybarn Theater, which is being renovated. But work has been thrown off-schedule by the some peculiar and unnatural activities. And after the potentially world-altering recent events of their previous assignment, the team thinks that a haunted theater (aren't they all?) will be a walk in the park.

Until they encounter the Phantom of the Haybarn -- an ancient evil whose ability to alter reality itself will test the skills, science, and blind luck of the Ghost Finders to the limit