Castle - Season 6 - Eps 3: 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.
About Castle

Title: Castle
First Air Date: 2009-03-09
Last Air Date: 2016-05-16
Status: Canceled
Rating: 7.988/10 (from 1954 votes)
Language: EN
Seasons: 8
Total Episodes: 173
Network: ABC
Genres: Drama, Crime
Production Companies: Beacon Pictures, Experimental Pictures, ABC Studios, The Barry Schindel Company, MilMar Pictures
Synopsis
After a serial killer imitates the plots of his novels, successful mystery novelist Richard "Rick" Castle receives permission from the Mayor of New York City to tag along with an NYPD homicide investigation team for research purposes.
Cast

Nathan Fillion
Richard Castle

Stana Katic
Kate Beckett

Molly C. Quinn
Alexis Castle

Jon Huertas
Javier Esposito

Seamus Dever
Kevin Ryan

Susan Sullivan
Martha Rodgers

Tamala Jones
Lanie Parish

Toks Olagundoye
Hayley Shipton