FX will promote the upcoming third season of the Denis Leary firefighter drama “Rescue Me” with an original 15-minute short that will be distributed exclusively across video-on-demand and broadband platforms.Exec producers Leary and Peter Tolan wrote the segment, “Rescue Me 2.5,” which centers on a mysterious creature the crew discovers in the firehouse. Regular cast members Leary, Jack McGee, Steven Pasquale, John Scurti, Daniel Sunjata and Michael Lombardi star. FX has sealed deals with Adelphia, Cablevision, Comcast, Cox, DirecTV and Reuters New York to make the short available on demand. AOL will have the exclusive broadband play, available for viewing between May 8-29, leading up to the premiere. New season of Sony Pictures TV-produced “Rescue Me” bows May 30.