Paul Turner is a widowed father of two teenaged boys, one of whom has spina bifida, rapidly approaching middle age, and used to dealing gracefully with all the challenges these things entail. Turner, however, is slightly different from others in his situation - he's openly gay and a homicide detective for the Chicago Police Department. Despite everything, his personal and family life is relatively placid. Until right now.

This time, his life couldn't possibly get more complex and problematic: there's a Science Fiction and Media convention in Chicago this weekend - one of the world's largest such gathering - and his sons are both attending. In full costume. And Paul Turner, like any good father, is going with them. If the prospect of that weren't bad enough, one of the convention's guests - one of the field's most successful fantasy writers - is found murdered, mostly likely by the broadsword found rammed through the corpse's chest. In most circumstances, a broadsword would be a unique murder weapon, but this time there are hundreds of attendees carrying similar ones as part of their costumes. Including his own son.

That one gruesome murder is just the beginning - the dead bodies amidst the revelers are starting to pile up - and Turner must sort through a confusing array of suspects in short order if he's to find the killer in time.