Karen Gillan gets some much-needed backup from Lena Headey, Michelle Yeoh, Angela Bassett, and Carla Gugino in “Gunpowder Milkshake,” an action pic that sees the “Guardians of the Galaxy” actress playing a hit-woman who finds herself in hot water. Sam (Gillan) was just 12 years old when her mother (Headey), an elite assassin, abandoned her, leaving the preteen to be raised by The Firm, the crime syndicate her mom worked for. Fifteen years have passed, and Sam has followed in her mother’s footsteps, but when a job goes terribly wrong and Sam chooses to protect an eight-year-old girl (Chloe Coleman) rather than serve The Firm, the organization turns their back on her. “You killed the wrong people. You’re no longer under our protection,” she’s told in a new trailer for the film.

Desperate for help, Sam reunites with her mother and her lethal associates, The Librarians (Yeoh, Bassett, and Gugino). Together, they vow to take down The Firm. “We’re going to bring the sky down on their heads,” Bassett says.

An alumna of “Doctor Who,” Gillan’s more recent credits include “Jumanji: The Next Level” and “Avengers: Endgame.” She made her feature directorial debut with “The Party’s Just Beginning,” a dark comedy about a woman grieving the death of her her best friend that made its North American premiere at the 2018 Tribeca Film Festival.

“Gunpowder Milkshake” hits Netflix July 14.