Serenity flies again! "Castle," the current home of Capt. Mal Reynolds -- a.k.a. actor Nathan Fillion, a.k.a. crime writer Richard Castle -- pulled the ultimate casting move when it brought in Fillion's "Firefly" costar Adam Baldwin -- a.k.a. Jayne Cobb - more

Just how easy was it for former Firefly co-stars Adam Baldwin and Nathan Fillion to find their old rhythm while shooting Monday's episode of Castle ? "It was like putting on an old pair of comfortable boots," Baldwin tells TVGuide.com with a laugh. "Al more

Castle  “Headhunters” Season 4 Episode  21 airs Monday April 16 at 10:00 p.m. on ABC. Episode Synopsis:  Castle “Headhunters” Season 4 Episode 21 – With tensions rising between Castle and Beckett, Castle finds himself a new p more

"With tensions rising between Castle and Beckett, Castle finds himself a new partner — Detective Ethan Slaughter (guest star Adam Baldwin, Firefly), a tough and colorful cop from the city's gang unit. But Castle gets more than he bargained more

With tensions rising between Castle and Beckett, Castle finds himself a new partner — Detective Ethan Slaughter (guest star Adam Baldwin, Firefly), a tough and colorful cop from the city's gang unit. But Castle gets more than he bargained for when Sl more