A young girl named Molly watches from the window as MIB agents neuralyze her parents after an alien visits their home. Instead of scarring her for life, it gives her a purpose: she wants to be the one in a black suit, making others forget what they saw. Years later, Molly (Tessa Thompson) brazens her way into MIB headquarters, where she impresses head agent O (Emma Thompson) enough to get a try-out. Christened Agent M, she’s sent to MIB’s London office, where she ends up assisting Agent H (Chris Hemsworth), who – like any good loose cannon – tells her he works alone and doesn’t need a partner. Soon, they’re in possession of an alien weapon and being hunted by a pair of paranormal twins and the MIB itself.