Y/N has been happily dating Chris Evans and Sebastian Stan, but her toxic ex-boyfriend suddenly comes back into her life. He refuses to accept that she has moved on and begins showing up everywhere—sending threatening messages, spreading lies about her relationship, and trying to convince Chris and Sebastian that Y/N is secretly seeing him. When the ex takes things too far and Y/N disappears after an argument, Chris and Sebastian realize just how dangerous the situation has become. Now they have to find her before her ex can hurt her, while Y/N fights to escape the man who refuses to let her go.