One Last Quiche

Tony Mandolin, San Francisco's only PI to the weird, is yanked into an alley by a large troll. Being faster than the troll, Mandolin is able to escape after only a few painful bruises. Back in his office, Franklin Jackson, Mandolin's somewhat reformed black ex-drag queen, brings in a case, someone is blackmailing the Restaurant Association. Tony accepts the case and immediately earns the ire of corrupt forces within the police.
Someone is poisoning innocent patrons with a poison that should not exist. Mandolin has to gain the help of the city's most powerful wizard, who happens to be a bad-tempered alcoholic, and also fend off the advances of Medb, the Dark Fairy Queen, who wants him as her slave and the main entree for a Dark Fairy Feast.
Only luck and determination, and the help of a top SF botanist do Mandolin and his friends manage to discover what the poison is and how to deliver the antidote. However, not before he is poisoned, beaten up by a troll and an old-style Mobster, and turned into a human marionette by a witch's apprentice.