Coastlines follows the story of ex-con Sonny Mann (Timothy Olyphant) as he returns home from prison after serving three years behind bars on drug charges. He quickly figures out that old enemies still have it out for him, while his old friends want Sonny to change his ways. All Sonny cares about initially is getting his $200,000 back that he is owed to him by his partners in crime. He also reunites with his old friend Ann (Sarah Wynter) who is now married to Sonny's best friend, Dave (Josh Brolin). Sonny ends up moving in with Ann and Dave, and quickly finds that he still has feelings for Ann. Meanwhile, Sonny's old business partner Fred Vance (William Forsythe), refuses to pay Sonny back despite his great wealth. This causes tension between the two rivals and Sonny must resolve his hatred of the past before it ends his new life just as soon as it begun.