Charisma Carpenter is seeing blue…

The 43-year-old part-Spanish American actress will guest-star on CBS’ Blue Bloods this fall, according to TVGuide.com.

Carpenter, best known for her role as Cordelia Chase on Buffy the Vampire Slayer and its spin-off series Angel, will portray Marianne Romano, a former popular girl in high school, who is now flashy, overly needy and just too obvious for a guy with a touch of class. Having had a fling with Danny (Donnie Wahlberg) several years back, she calls on him for help when her abusive-fiancée strikes her in a fit of ‘roid rage.  But her attempt to tweak Danny’s heartstrings backfires when it results in a police investigation of her boyfriend.

Carpenter first announced the news on Twitter. “Playing ‘Marianne’ on [Blue Bloods] is the most fun I have had [with] a character in a long time. Staten Island accent and a lot of leopard!”

Carpenter’s television credits include appearances on Supernatural, Greek and The Lying Game.

Blue Bloods returns to CBS this season on Fridays at 10:00 pm ET.

Carpenter’s episode is slated for November.