- "You saw what happened to Emily. Sam got angry. Lost it for a split second. He'll never be able to take it back."
Sam Uley was abandoned by his father at a young age. For this reason, he grew up as a very mature person and took matters very seriously. In high school, he dated Leah Clearwater. Sam first phased around the time the Cullens moved back to Forks. When his power awakened, he remained in his wolf form for over one week before he finally became human again. Since he had no guidance at the time, he didn't know what happened to him until the Quileute elders (Billy Black, Quil Ateara III and Harry Clearwater) explained to him about the Quileute's magic, something he had only thought of as myths and superstition.
Emily Young was second cousins with the Clearwater siblings, living outside on the Makah reservation at the time. She was especially close to Leah. Before Sam phased, she had met him countless times and was very fond of him.
After finishing high school, she began teaching art at the high school on the reservation and local college.
After Sam returned to his human form, he imprinted on Emily when she came to visit her cousin Leah, causing Sam and Leah to end their relationship. Emily and Sam tried to stay away from each other, but he found the distance too much to handle and eventually went to visit her. Despite her newfound feelings for Sam, she continued to struggle due to her desire not to hurt Leah. When Sam revealed the truth and phased in front of her, she was thrilled; Sam, happy to please her, introduced her to the rest of the pack as they began phasing. Despite becoming closer to Sam with every visit, Emily still told herself that it was all to get Sam to return to Leah.
When Emily realized that people were talking about her and Sam, and therefore Leah had likely heard rumours, she met him in the forest and forbid him to ever come to her or contact her again. Sam was devastated, but he knew that if it made Emily feel better he had no choice but to obey. She then told him that she wanted him to go back to Leah. This was the only thing he was able to refuse her; he loved Leah still, although not in the same way, and didn't want her to be stuck with somebody that didn't love her and longed for somebody else. Angry at herself and not knowing what to do, Emily lost her temper and shouted at Sam that he was just like his father, running away from his responsibilities. The insult was far worse than Emily had anticipated, and caused Sam to lose control of himself. This resulted in Sam losing control of his anger for a short second when she was standing too close; he accidentally phased in front of her and slashed the right side of her face, creating deep scars that distorted her features, pulling down the corner of her eye and her mouth.
Thinking that he had killed her, Sam was hysterical; he couldn't calm down enough to phase back. Luckily Jared was in wolf form and found out what had happened, and he rushed to their side with Sue Clearwater. Emily regained consciousness, and was struck by how horrified Sam and Jared were by what had happened.
At the hospital, she explained to the doctors that she was attacked by a bear up north during salmon spawning season in order to protect the tribe's secret. Eventually she was visited by Sam, who looked at what he had done and asked her to tell him to commit suicide to end his pain; he couldn't even do that without knowing that his death was what she wanted. Emily told him that she wanted him to live, and forgave him; she realized that despite everything she loved him too, and didn't feel complete without him by her side.
They finally gave in to their feelings and became a couple, and eventually became engaged. Emily gathered her courage and told Leah, which ended their friendship. Sam has never forgiven himself for hurting Emily.
- Main article: New Moon
As other Quileute youngsters begin to phase, Sam takes the responsibility of guiding them and ensuring the protection of their reservation. Emily engages in feeding and taking care of them.
Their relationship takes a serious turn when Leah, Emily's cousin and Sam's ex-girlfriend, unexpectedly joins the pack. Though Leah had found new understanding to the situation and forgave them, she still finds it hard to be around Sam and be constantly reminded of how much she still feels for him, and how he will always know how she feels because of their telepathic link in the pack.
- Main article: Eclipse
Sam, Emily and Leah's triangle story is explained by Jacob when he talks to Bella about imprinting. According to him, Sam has hated himself for hurting Leah so deep, but cannot undo what he'd done.
Sometime after Leah phased, Sam and Emily are forced to deal with her and her relentless pain over losing Sam, even though she has forgiven them and agreed to be Emily's bridesmaid. Because they share a telepathic link to each other, Sam and Leah are constantly reminded of what they went through and she is still going through, and she takes it out on the entire pack by letting them feel her pain.
- Main article: Breaking Dawn
In the midst of Breaking Dawn, Leah tells Jacob that she loves Sam enough to be happy for his happiness with Emily but refuses to see it, because it is unbearable for her to watch and be constantly reminded of how much she still feels for him.
During Christmas Day, Emily and Sam visit Charlie to make a celebration facade with the Cullens and Jacob's pack.