Lombard Street is a Star Trek fanfiction set in the crossover AU, The Ancient Destroyer Cycle, featuring TOS characters Sean Finnegan and Gary Mitchell. It is written by Rob Morris.
When a child on a colony world is gunned down for no apparent reason, Colonial Affairs Commisioner Heichiaro Nogura asks up-and-coming officer Finnegan to oversee the investigation. But is prankster Finnegan the one being played, and what price will he pay for crossing the wrong people?