Erica Peeples is a 17-year old Midshipman on the USSA ship Orsino, is the daughter of Gene Peeples and Gretchen, and the stepdaughter of Linda Bailey-Peeples. She enjoys that her singing annoys her father. Gene mentions that Erica has received commendations for both being particularly vigilant against Jupiter Spies, and for holding her own against a crew of MurderMen.
Erica is in a relationship with Ensign Lewis Bambrill. She has a combative relationship with her stepmother, Linda. She is able to successfully escape the destruction of the Orsino with her father, stepmother and Ensign Bambrill.
In MurderMen, Erica is aboard the USSA Olivia during the MurderMen invasion of Earth. The Olivia is eventually boarded and taken over by the MurderMen. Erica awaits her father in an escape craft at the other end of the ship from Gene, Cactoid Jim, Chicky Sullivan and The Red Plains Rider. Linda leaves the safety of the escape pod to run to the armory for more weapons, but along the way back is bitten by a MurderMan and becomes MurderManned. Erica is forced to shoot her step-mother, but is bitten by her first. By the time Gene and the others arrive, it is too late and Erica knows she will soon become a MurderMan herself. She explains her step-mother's death, and calls her "mom" for the first time.
She then begs for her father to kill her before her transformation is complete and she has the desire to MurderMan or ManMurder her father or anyone else. Gene finds that he cannot bear to do so, thus The Red Plains Rider shoots and kills Erica instead. She thanks Red for this act before she dies.