ON BACK-TO-BACK EPISODES OF ABC'S "CASTLE," MONDAY, DECEMBER 20

ABC will air back to back episodes of "Castle" -- last season's closer, followed by this season's opener -- MONDAY, DECEMBER 20 (9:00-11:00 p.m., ET).

First, in "A Deadly Game," nothing is as it seems when Castle and Beckett investigate what appears to be the assassination of an intelligence operative. Meanwhile, Beckett's romance with Demming threatens her relationship with Castle, forcing them to confront their feelings for each other. Stephen J. Cannell, Michael Connelly and James Patterson guest star as themselves playing poker with Castle (Rebroadcast. OAD 5/17/10).

Then, in "A Deadly Affair," Castle has been absent since leaving for the Hamptons months ago to finish his second Nikki Heat novel, so when Beckett and her team burst into a shadowy apartment on the trail of a murderer, the last thing they expect to see is the real-life Castle standing over a dead woman's body holding a gun! As Castle protests his innocence, Beckett has no choice but to arrest him on suspicion of murder (Rebroadcast. OAD: 9/20/10).

"Castle" stars Nathan Fillion as Richard Castle, Stana Katic as NYPD Detective Kate Beckett, Susan Sullivan as Martha Rodgers, Molly Quinn as Alexis Castle, Ruben Santiago-Hudson as NYPD Captain Roy Montgomery, Tamala Jones as Medical Examiner Lanie Parish, Jon Huertas as NYPD Detective Javier Esposito, and Seamus Dever as NYPD Detective Kevin Ryan.

Guest starring in "A Deadly Game" are Michael Trucco as Tom Demming, Monet Mazur as Gina, Stephen J. Cannell as himself, Michael Connelly as himself, James Patterson as himself, Mitch Pileggi as Hans Bremel. The spisode was written by Andrew Marlowe and directed by Rob Bowman.

Guest starring in "A Deadly Affair" are Michael Rady as Evan Murphy, Charlene Amoia as Ana Marie, Gino Cafarelli as Dean Carbino, Justice Gamble as bartender, Lisa O'Hare as Kitty Canary, Craig Gellis as Earl Moreland. The episode was written by Andrew Marlowe and directed by Rob Bowman.

"Castle" is broadcast in 720 Progressive (720P), ABC's selected HDTV format, with 5.1 channel surround sound. This program carries a TV-PG,L,V parental guideline.

For more information on "Castle," visit ABC.com