Eleazar and Carmen met while Eleazar was affiliated with the Volturi. Since Carmen possessed no useful skill whatsoever, she was not invited into the coven, nor was she interested in joining. Eventually, Eleazar grew tired of the Volturi's lifestyle and left with Carmen to find a new life; Aro granted him permission to leave since he saw no need to hold on to his gift at that time. Carmen and Eleazar eventually relocated to Denali and met the Denali sisters: Tanya, Kate, and Irina, who learned to control their thirst by adjusting their diet to animal blood. Tanya invited Carmen and Eleazar to stay with them and try "vegetarian" lifestyle. Eleazar and Carmen warmed up to Tanya and her sisters so much that they made their stay permanent.
Edward has mentioned that both Carmen and Eleazar are very compassionate for vampires and that if they had not found the Denali sisters, they would have eventually found another compassionate way of life.
- Main article: Breaking Dawn
Carmen and Eleazar first appear in Breaking Dawn when they attend Bella and Edward's wedding, along with Tanya and Kate, as a way of apologizing to the Cullens for leaving them in times of need. Both show fondness of meeting Bella, and welcome her to the family.
Three months after the wedding, Carlisle calls them to Forks after Irina misidentifies Bella and Edward's biological daughter, Renesmee to be an immortal child and reports to the Volturi. When the Cullens try to explain, Eleazar, Tanya and Kate show the same prejudice as Irina and refuse to listen to their explanation, until Carmen willingly allows Renesmee to tell the story herself. After she is persuaded that the child is a vampire hybrid, she convinces Eleazar to let her explain the story herself, and then Kate and Tanya. After the misunderstanding is cleared up, they agree to help the Cullens testify against the Volturi's accusations, who are on their way to kill the family for a false report by Irina.
Eleazar and Carmen stand with the Cullens during the trial, and when it ends peacefully with only the death of Irina, they return to Denali with a new member, Garrett, who has joined them as Kate's new mate.