CASTLE HAS TO CONTEND WITH A NEW DETECTIVE IN TRYING TO SOLVE THE MURDER OF A EARLY 90S TV STAR, ON ABC'S "CASTLE"

Antonio Sabato Jr. and Lisa Edelstein Guest Star

"Need To Know" - With Beckett still in D.C., Castle and the boys investigate the murder of former child star Charlie Reynolds, who rose to fame playing the lovable nerd on an early 90s High School sitcom. But the case takes a turn for the strange when Agents Beckett and McCord arrive from Washington to take over the investigation, creating competitive tension in the precinct. But why would a washed-up actor's death warrant Federal scrutiny? Whatever the reason, Beckett and McCord aren't telling. Meanwhile, Castle has to contend with a new face at the 12th, NYPD Detective Frank "Sully" Sullivan (Joshua Bitton, "The Pacific"). Antonio Sabato, Jr. ("Melrose Place," "General Hospital") guest stars as Ramon Russo, the victim's former sitcom costar, on "Castle," MONDAY, OCTOBER 7 (10:01-11:00 p.m., ET) on the ABC Television Network.

"Castle" stars Nathan Fillion as Richard Castle, Stana Katic as NYPD Detective Kate Beckett, Susan Sullivan as Martha Rodgers, Molly Quinn as Alexis Castle, Penny Johnson Jerald as NYPD Captain Victoria Gates, Tamala Jones as Medical Examiner Lanie Parish, Jon Huertas as NYPD Detective Javier Esposito, and Seamus Dever as NYPD Detective Kevin Ryan.

Guest Cast: Antonio Sabato, Jr. as Ramon Russo, Lisa Edelstein as Rachel McCord, Joshua Bitton as Grant "Sully" Sullivan, James Patrick Stuart as Ethan Wright, Myko Olivier as Pi.

"Need To Know" was written by Elizabeth Beall and directed by Larry Shaw.

"Castle" is produced by ABC Studios. Andrew Marlowe serves as executive producer/writer, along with executive producers Rob Bowman, David Amann, David Grae, and Armyan Bernstein.

"Castle" is broadcast in 720 Progressive (720P), ABC's selected HDTV format, with 5.1 channel surround sound. A TV parental guideline will be assigned closer to airdate.

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