While watching movies at his place with Anya, Buffy and Riley, Xander decides it's time he moved out of his parents' basement.
The next day, he and all of his friends view an apartment that he's interested in. The apartment seems perfect, but he doubts he can afford it since his construction job will be finishing soon. Xander's reluctance to get the apartment angers Anya, who's already irritable due to a dislocated shoulder.
Meanwhile, as Giles unpacks stock for the magic shop, he is confronted by a demon named Toth. Toth is looking for the Slayer so that he can kill her and when he finds that she's not there, he leaves.
Later, Giles remembers that the demon had a very distinct smell and he and the gang then go searching for Toth at the junkyard. Toth appears and fires a weapon at Buffy. He misses and instead hits Xander, sending him hurtling backwards into a pile of trash. Toth flees and the gang go to Xander's aid. They help Xander up and then walk him home, but what they don't know was that there is another Xander left lying in the trash.
The next morning, the Xander in the junkyard wakes and returns home. He looks through his basement window to see his double getting ready for work.
Confused and in need of some help from Buffy, he tries to call her on a public phone. However, when he sees his double pass him on the way to work, he puts down the phone and follows.
At the construction site, the Xander from the junkyard watches his double get promoted. He also follows his double to the apartment he viewed the day before and listens outside the door as his double confirms that he will be renting it.
When the double leaves the apartment, Xander jumps him. His double punches him and runs off.
Xander (the one who woke in the junkyard), realizes that he must get help and goes to Giles to look for Buffy. However, he's too late. His double got there first and has already convinced Buffy, Riley and Giles that he is the real Xander.
Since he can't go to Buffy for help, Xander goes to see Willow and tells her what has happened. Willow deduces that his double must be Toth, and Xander suddenly becomes worried Anya may be in danger if she is with him. Xander goes looking for Anya at her apartment, only to find an phone message from his double asking her to meet him at the new apartment.
Willow goes to Giles to explain to everyone that the real Xander was actually with her, and Giles makes a discovery. Both Xanders are real. The weapon that Toth had used was meant to split Buffy into two people, so that he could kill the weaker Buffy. Instead, it had split Xander into two - each with different personality traits.
Buffy and Riley rush off to find the Xanders to let them know what has happened and stop them from harming each other.
Meanwhile, at the new apartment, Anya admits to the more mature Xander that her recent injury has made her think about her mortality right before the insecure Xander bursts in carrying a gun and threatening to kill his double.
Buffy and Riley arrive just in time and explain to the Xanders what has happened to them. Their explanation is interrupted when Toth enters the apartment, but Buffy manages to kill Toth quickly.
Later, Willow breaks the spell that is keeping the Xanders apart and he becomes one person again.