The episode opens with Gunn still being tortured by a demon in a hell dimension, when he is suddenly rescued by Illyria, who uses her ability to shift between dimensions to return them both to Wolfram & Hart. Angel grows suspicious of Illyria's continued presence at the firm, and concludes that she is staying not out of loyalty, but out of an attraction for the firm's power. He orders Lorne to shadow her, and then turns his attention to a legal case involving a ceremonial demon pact; a pregnant woman has agreed to allow a demonic cult called "the Fell Brethren" to adopt her baby, and Angel and Gunn start to advise her until they learn, to their outrage, that their client isn't the innocent woman, but rather the seemingly benevolent demons who are secretly taking advantage of her and plotting to sacrifice the child not long after the birth.
Meanwhile, Illyria enjoys sparring with Spike in the training room, but elsewhere begins to act oddly even by her standards, and Wesley theorizes that she is growing emotionally and molecularly unstable as a result of her interdimensional travels; if her energy excess continues to go unchecked, it will result in a catastrophic explosion.
As Angel, Gunn, and Hamilton argue over how to handle the Fell Brethren case, Illyria grows increasingly disoriented and paranoid, culminating in a confrontation in which she effortlessly kills Angel, Lorne, Spike, and Wesley in a matter of seconds. At this point, the narrative switches to her point of view, and we learn that her disorientation has been caused by the fact that her excessive mystical energy has been sending her back and forth in time uncontrollably.
Illyria again goes back in time to a point before she had killed the other characters, and inadvertantly begins taking Angel with her on her trips through time. Angel learns of the deaths of his friends, and is horrified. After Illyria gives him advice about power, she explodes and likely decimates the continental shelf, but the explosion is so powerful it blasts Angel back in time to before Illyria killed everyone. This time, thanks to what Illyria told him, Angel is able to avoid the massacare. Illyria accuses Angel and Wesley of plotting to kill her with Wesley's massive ray gun, but Wes reveals that the gun is not meant to kill her, but rather to disperse her excessive energy and thus prevent the fatal explosion. Wesley manages to activate the ray in time, but Illyria is left emotionally devastated by the resulting loss of some of her super powers.
In the epilogue, Angel returns his attention to the Fell Brethren case, and shocks Gunn by agreeing to represent the demons rather than the pregnant woman, having apparently taken Illyria's advice about power.