Rootbeer Films has completed “2nd Unit: Invisible Action Stars” with James Cameron, Keanu Reeves, Mark Wahlberg and Halle Berry, Variety has learned exclusively.

The film explores relationships between actors and stunt performers — a topic at the heart of Quentin Tarantino’s recent “Once Upon a Time in Hollywood.” Joe Mantegna narrates “2nd Unit: Invisible Action Stars.”

Lenny Shapiro, CEO/President of Rootbeer Films, said, “Having produced many action films, it is my great pleasure to showcase the real action stars… the stunt people.”

The documentary features Heidi Moneymaker, Jackson Spidell, Jack Gill, JJ Perry and Jessie Graff and explores the relationship between the actor and the stunt performer. Additional featured interviewees include Zoe Saldana, Chad Stahelski, Jon Bernthal, Shemar Moore, Joseph Gatt, Mark Dacascos, and Helen Mirren.

The film was produced by Rootbeer Films in conjunction with In The Light Productions, and was directed by Jason Strickland, known for his work as Scott Greene in “The Secret World of Alex Mack.”

Strickland also produced along with Johnnie L. Smith and Taran Butler. Shapiro executive produced with Steven B. Phillips, Gregory J. Gonzalez, Jack Gill and Katie O’Donovan. Rootbeer, which is handling sales, has also begun production with In the Light on “Hollywood’s Hard Hitters,” a female version of “2nd Unit: Invisible Action Stars” with Zoe Saldana and Mary Elizabeth Winstead.