Crossover episodes

Following the third season of Buffy the Vampire Slayer, David Boreanaz who plays Angel went off to star in his character's own spin-off show Angel, as the main protagonist, and was also joined by Buffy co-star Charisma Carpenter who played Cordelia Chase. Both the fourth season of Buffy the Vampire Slayer and the first season of Angel began broadcasting on the WB Network on October 25 1999 and finished on May 23 2000. Buffy would be broadcast at 8pm EST while Angel would immediately follow at 9pm EST. The timeline and events of Buffy and Angel would run alongside each other and references would often be made by what was happening in Sunnydale (the home of Buffy) and what was happening in Los Angeles (the home of Angel).

This tradition would continue with the fifth season of Buffy and the second season of Angel running alongside each other, the sixth season of Buffy and the third season of Angel running alongside each other, the seventh and final season of Buffy running alongside the fourth season of Angel while the fifth and final season of Angel would standalone.

The following list is an indication of crossover episodes shared between Buffy the Vampire Slayer and Angel.

"The Freshman" and "City of"
In the first episode of Season 4 of Buffy, "The Freshman ", Buffy calls around to her mother's house and gets a phonecall. She answers the phone only to get no response from the caller. The caller then hangs up abruptly. In the first episode of Season 1 of Angel, "City of ", we learn that the caller is actually Angel. Angel is brooding in his room and calls the Summers' household but hangs up quickly after hearing Buffy answer the phone.

"The Harsh Light of Day" and "In the Dark"
In the third episode of Season 4 of Buffy, "The Harsh Light of Day", Buffy and the Scooby Gang manage to forcefully obtain the Gem of Amarra from Spike, a magical ring that makes vampires indestructible as long as they are wearing the ring. Not wishing that Spike uses it for evil, Buffy believes Angel should have it to do good. Oz, who has an upcoming gig in LA, promises to take the Gem to Angel while he's there. In the third episode of Season 1 of Angel, "In the Dark", Oz calls around to Angel Investigation offices and gives the Gem to Angel while also helping Angel, Cordelia and Doyle in making sure the Gem doesn't fall into the hands of evil. Spike also shows up in LA in an attempt to take back the Gem.

"The Bachelor Party", "Pangs" and "I Will Remember You"
At the end of the seventh episode of Season 1 of Angel, "The Bachelor Party ", Angel's half demon friend Doyle has a vision of Buffy experiencing difficulty in fighting a foe. Spurred on by Buffy being in serious danger, Angel shows up in Sunnydale in the eight episode of Season 4 of Buffy to help her fight a tribe of vengeance seeking resurrected Native Americans. Angel makes sure not to be seen by Buffy and she is unaware of his presence in Sunnydale until Xander accidentally lets it slip at the end of the episode. In the ninth episode of Season 1 of Angel, Buffy shows up at Angel Investigation offices and demands to know why Angel never met her in person while in Sunnydale. She then helps Angel on a quest to fight a demon.

"This Year's Girl", "Who Are You", "Five By Five", "Sanctuary" and "The Yoko Factor"
In the Buffy Season 4 two parter, the fifteenth and sixteenth episodes titled "This Year's Girl " and "Who Are You " respectively, rogue Slayer Faith Lehane wakes from a coma and begins to wreak havoc in Buffy's life once again. At the end of "Who Are You", Faith escapes Sunnydale by train. She turns up in LA in the the eighteenth and nineteenth episodes of Season 1 of Angel, titled "Five by Five " and "Sanctuary " respectively, and is hired by law firm Wolfram & Hart to kill Angel. Buffy also appears in "Sanctuary" to stop Faith. This would mark Buffy's final appearance on Angel. In the twentieth episode of Season 4 of Buffy, "The Yoko Factor ", Angel reappears in Sunnydale to talk with Buffy and also meets her new boyfriend Riley Finn.

"Fool for Love" and "Darla"
In Buffy Seaon 5, Episode 7, titled "Fool for Love ", Spike has many flashbacks about his life with his vampire family of Darla, Angel and Drusilla. In Season 2 of Angel, Episode 7, titled "Darla ", Darla has many overlapping flashbacks with Spike about life with his vampire family of Angel, Drusilla and Spike.

"The Trial" and "Crush"
In Angel Season 2, Episode 9, titled "The Trial ", Drusilla makes her first present tense appearance on that show. She later returns to Sunnydale in Buffy Season 5 Episode 15, titled "Crush ".