Alex (Olga Kurylenko), a trained ex-military agent-turned-thief, gets pulled into a high-tech bank heist (her 'one last job') by her former partner Kevin. During the heist, they steal a bag of diamonds which hides a valuable flash drive containing incriminating evidence. Alex keeps the diamonds as her cut of the heist and relaxes at a hotel as the rest of the proceeds are laundered. They are pursued by a team of agents led by Mr. Washington (James Purefoy). Kevin is tortured and killed as Alex hides under the bed. Alex escapes and is involved in a cat-and-mouse chase across the city. Kevin's wife and child are used as bait to lure Alex. Alex tries to uncover the conspiracy behind her pursuers. Alex eventually learns they have been sent by an anonymous United States Senator (Morgan Freeman) to retrieve the flash drive.

Momentum was Stephen Campanelli’s directorial debut. Written by Adam Marcus and Debra Sullivan

The film stars Olga Kurylenko as the protagonist "Alexis", James Purefoy as the antagonist "Mr. Washington", and Morgan Freeman as the U.S. senator. Vincent Cassel was originally to star opposite Kurylenko, but was replaced by Purefoy. Director Campanelli wanted to cast Purefoy based on his performance in the television series "The Following". Freeman offered his services to Campanelli for his directorial debut based on their prior working relationship, when he was a cameraman for Clint Eastwood.

The film had its world premiere at the 2015 Fantasia International Film Festival, on July 22, 2015, in Montreal, Quebec, Canada, the hometown of the director. The film was released in the United States on October 16, 2015.