'Castle' Spoiler Bits: Bloody Good Casting and the Return of 3XK
'Castle' Spoiler Bits: Bloody Good Casting and the Return of 3XK
Laurel Brown
Laurel Brown
Senior Writer, BuddyTV
If you go by just what Castle has already told us about the upcoming season, we're in for a pretty wild ride over the next few months. From guest stars to love interests to returning bad guys, these spoilers are enough to tantalize any fan.

True Blood Vampire to Guest Star
A report from TVLine names the newest in a long line of season 4 Castle guest stars: Jessica Tuck of True Blood. Tuck will appear as a wealthy woman who is a benefactor of a museum. When murder occurs, of course she becomes a suspect.

Fans of True Blood will recognize Jessica Tuck as the show's vampire political mouthpiece, Nan Flanagan. A regular for the first time in this season of True Blood, Tuck's character actually appeared before the show even debuted, featuring in its viral advertising.

This is the same episode in which Kristin Lehman will appear as Martina Kaye, an insurance investigator who "sparks" with Castle. The date of the episode is uncertain, but it's definitely sounding like art will be intricately entwined with violence for this installment.

The Return of 3XK
The killer last seen in the season 3 episode, "3XK," will return for season 4. EW.com reports that the 3XK killer, played by Michael Mosely, will reemerge in a plot that brings up "a side of Ryan you've never seen before." Since 3XK was last seen disappearing with Ryan's gun and messing with Castle's head, we can imagine that there will be a lot of unfinished business between the characters.

The 3XK-return episode will be entitled "Kick the Ballistics" and will feature a couple of prominent guest stars in addition to Mosely's Jerry Tyson (aka, 3XK). Ross McCall, most recently seen playing Neal Caffrey's archrival Keller on White Collar, will play a policeman, while Francois Chau -- Dr. Pierre Chang from all those Dharma videos on Lost -- will also appear.

Can we expect 3XK claim a few more victims? Will Ryan's gun do bad things in 3XK's hands? Will Ryan do worse things? And how will Castle react to the killer who messed with his head before getting away?

Want more Castle scoop? Check out our Castle Ultimate Fan Page on Facebook.

Castle's fourth season will begin on Monday, September 19.

(Image courtesy of ABC)