Written by Brent Fletcher and it was the directorial debut of David Boreanaz, who plays Angel, and was originally broadcast on January 21, 2004, on the WB network.
In "Soul Purpose", guest star Christian Kane returns as Lindsey McDonald, taking on the deceased Doyle's name in an attempt to convince Spike that he is the vampire champion mentioned in the Shanshu Prophecy.
Meanwhile, Angel slips into a feverish hallucinative state in which he dreams that his destiny of redemption is claimed by Spike.
In Angel's dream, he relives the moment in which Spike drinks from the cup that signifies he is the champion referred to by the Shanshu Prophecy.
She pulls out a fishbowl, calling the dead goldfish inside it Angel's soul, and says that they will have to flush it and hands it to the bear standing next to her.
Fred turns back to Angel and tells him that she cannot find anything wrong with him but thinks he is empty inside.
A blue fairy floats in and sprinkles gold dust on Spike, making his heart beat again.
Wesley and Gunn head back to Wolfram & Hart and tell Fred that Spike thinks they have sold out.
Angel sits in a chair in the middle of a sunny field as the gang approach him and assure him he can stay there as long as he likes.
Later, the gang and Eve gather in Angel's room and Wesley explains that the creature was a parasite which makes the host oblivious to its presence and causes hallucinations.
Adam Ward, the first assistant/focus puller, says although Boreanaz "didn't have the cinematographer's vernacular", he was able to accurately describe how he wanted the scenes to look to director of photography Ross Berryman, doing a "phenomenal job" for his directorial debut.
[1] In an interview with Sci Fi Weekly, Boreanaz says some of his original ideas for this episode needed to be "toned down" by executive producer Jeffrey Bell: "I had to remind myself that I am shooting an Angel show and not this crazy, cinematic, swooping thing"[2] although producer Kelly Manners "really allowed me the opportunity to do some things a first time director wouldn't normally be allowed to do.
Boreanaz had just had reconstructive surgery on the ACL of his left knee, which is why he spends most of this episode immobilized in bed.
News of Christian Kane's return was leaked over the internet before this episode aired,[5] but writer Brent Fletcher explains that they had anticipated this.