Castle - Season 4 - Eps 2: Heroes & Villains
When an ex-con is mysteriously slain in an alley, Castle and Beckett believe a vigilante is behind the murder. But efforts to identify their suspect are thwarted when they discover that he roams the city in a Superhero costume – and may indeed be a Superhero. Can they capture and unmask the killer before he strikes again?
About Castle

Title: Castle
First Air Date: 2009-03-09
Last Air Date: 2016-05-16
Status: Canceled
Rating: 8/10 (from 1953 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