Angel

David Boreanaz, who stars in The WB’s vampire series Angel, told SCI FI Wire that this week’s episode, guest starring Buffy the Vampire Slayer co-star Alyson Hannigan, sets up Boreanaz’s upcoming crossover to Buffy. Hannigan’s character, Willow, appears in the March 19 episode to help deal with Angelus, Angel’s evil alter ego.

"There’s going to be a lot of stuff that she does that’s going to bring up some things for Angel and reasons why he’s going over to Buffy," Boreanaz said in an interview. "It’s really going to be interesting to see in the next six or seven episodes how Angel actually gets over to see Buffy and why he’s going back over there."

Boreanaz added that both Buffy and Angel will offer clues to viewers that sets up Buffy’s series finale in May, on which Boreanaz will appear in a guest role.

As for Hannigan’s guest spot on Angel, Boreanaz said it was nice to see her work with real-life fiance Alexis Denisof, who plays Wesley. "It’s good to see her and Alexis together, since the two of them are getting married in real life," Boreanaz said. "It was good to see her and have her back into the swing of our story. ... They were loving it. I’m sure that any chance you have an opportunity to work with somebody you’re so close to really brings out really fun chemistry and a strong sense of relationship, and that definitely shows." Angel airs Wednesdays at 9 p.m. ET/PT.