Episode 78 of "Angel"
s04e12 Calvary

The gang rush to confront Wo-Pang about the missing soul, but he doesn't have it. When they arrive home they find Lilah on the cameras, talking to Angelus about 'taking care of The Beast'. They follow her and discover the information that Wolfram & Hart stole from Lorne's head. Cordelia has a vision. Angelus continues to reveal embarrasing secrets, while Gunn and Connor retrieve the head of a soul eater seen in Cordelia's vision. The gang perform a spell using the head and Angel returns. Cordelia opens Angel's cage a little too eagerly, but Angelus comes out, throws her against the bars and escapes. The gang set out to find him, while Cordelia and Lilah stay at the hotel. Angelus returns, knocks Cordelia out and chases Lilah. After a long chase, she bumps into Cordelia. "He's going to kill us!" Lilah says. Cordelia stabs her in the neck and replies... "Why do you think I let him out, you stupid bitch?"