Luke was a man who had the power to send someone forward or backwards through time. His victims do not remember the time that passes during the jump, but Luke does. He presumably used this power on mulitple women to get them to love him, but these attempts presumably never worked.
He meets Jess after she has a fight with Rudy. After they spend the night together, she tries to leave, making Luke angry at her. So, Luke uses his power on Jess to send her one year into the future. In this future, Jess and Luke have a son together, whom Luke uses to try to convince Jess to stay. Luke tells her to spend some time with their son as he believes Jess wouldn't be able to leave her son, which ultimately becomes true.
After Rudy dies in this alternate future Jess decides that she cannot stay in Luke's timeline. She records a message to send to her past self and then kills herself by slitting her wrists. A panicked Luke then finds her body and reverses time to save her. However, "past Jess" sees a message on her phone that "future Jess" recorded explaining that Rudy dies in Luke's timeline, but she has a son that she loves. So, to save Rudy and still have her son, she has sex with Luke in the bar, then killing him to stop his trapping her again.
- Time Jumping - Luke could send people forward and/or backward through time.