The film “Sergeant Rex” (original title: Megan Leavey) is based on a true story and tells the moving story of the young US Marine Megan Leavey and her military dog Rex.
Megan Leavey (played by Kate Mara) is a young woman who is struggling to find her footing in life. She decides to join the US Navy and is transferred to the K9 unit, which specializes in training sniffer dogs. There she meets Rex the sheepdog, who is considered particularly difficult. But with a lot of patience and determination, Megan wins his trust and the two become an inseparable team.
Together they are sent to Iraq, where they complete numerous dangerous missions. Their main task is to detect explosives in order to protect the lives of their comrades. During one mission, an explosion occurs in which both Megan and Rex are injured. Megan is honorably discharged as a result, but Rex remains in the service.
Back in the US, Megan fights to adopt Rex and give him a safe home. She works tirelessly for his welfare and launches a public campaign. After many setbacks, she finally succeeds in taking Rex home with her, where he can spend the rest of his life in peace.