It has a great concept, cast and script, and it's executed crisply by Gina Prince-Bythewood. This film makes her the first black woman to direct a big budget, star-driven action movie, which already makes it worth the watch, and Prince-Bythewood's assured direction makes it a worthy one too.

The Old Guard refers to a group of immortals, an "army" of sorts, or at least a sleeper cell of four warriors, led by Andy (Charlize Theron, pictured), who have been around for centuries. They're moral mercenaries, fighting for what they believe in.

Andy, the oldest of the guard, has led the life of a mysterious, legendary warrior, keeping a low profile in the modern world while saddling up for special missions.

When a rescue op turns out to be a setup and a new warrior of their kind (KiKi Layne) pops up in Afghanistan, Andy has to scramble for her team's survival, even though survival, for them, is the easy part. Captivity for an immortal is the very, very hard part.

Greg Rucka adapts his own graphic novel series for the screen, and he delivers a fantastic script - modern but rich in mythology.

This supernatural-ish concept is grounded and deeply human, wrestling with love, loss, destiny, betrayal and the ultimate question if what we're fighting for here on Earth is worth it. Theron always seems superhuman, so this is an easy role for her. She delivers a captivating performance that isn't in any way showy, but subtle and sensitive.

What makes The Old Guard fascinating is not necessarily the fight scenes or action sequences, but the conversations the characters have about what they've chosen to do with the immortality they never chose for themselves.