Five years ago, Mike Dowling published Sergeant Rex, a memoir about the bond he’d forged with a bomb-sniffing dog while serving in over 35 missions in Iraq. Now, Marine Corporal Megan Leavey, is the subject of a documentary drama — based on a true story — that portrays her relationship with the same German shepherd dog.

Directed by Gabriela Cowperthwaite, the film stars Kate Mara as the title character, with Edie Falco and Will Patton in support roles.

At the point of departure, we find Megan enlisting in the Marines. After completing basic training on Parris Island, she finds her true calling in the Corps when she is assigned to the K-9 unit. Rex, who has become uncontrollable, is on the verge of being declared unfit for active duty by the base’s veterinarian, Dr. Turbeville (Geraldine James). Fortunately a dog lover begs that someone be given an opportunity to soothe and tame Rex.

Drill Sergeant Martin (Common) intervenes on Megan and Rex’s behalf and gives her the chance to work with the dog. With the patience of Job, Megan shows that she has the touch necessary to tame Rex. The two become inseparable and they’re shipped overseas to search for IEDs buried in the dangerous desert sands of Iraq’s Anbar province.

The deployment is uneventful, until Megan and Rex are injured in an explosion and shipped back to the States for rehabilitation at facilities far apart from each other. However, Megan’s attachment to Rex drives her to find a way to obtain possession of Rex. The remainder of the movie depicts her cutting through bureaucratic red tape until she finally succeeds in achieving ownership of Rex.

Very Good (***). Rated PG-13 for violence, profanity, mature themes, and suggestive material. Running time: 116 minutes. Production Studio: LD Entertainment. Distributor: Bleeker Street Media.