Kyle Wincott (THE FLASH's Robbie Amell) is a U.S. Marine. He serves with another U.S. Marine, Max -- who just happens to be a very highly trained dog.
When Kyle is killed in an attack trying to save Max, the PTSD-stricken dog is taken out of service, and will be put down unless Max's family takes him. The Wincott family -- hard-as-nails former Marine and father Ray (Thomas Haden Church, HEAVEN IS FOR REAL), mother Pamela (Lauren Graham, GILMORE GIRLS), and cynical teenage Justin (Josh Wiggins, HELLION) -- are willing to take Max in because they see him as a family member.
But Max has a secret. One of Kyle's hometown buddies and fellow Marine was running guns, and is to blame for the attack that got Kyle killed. When he comes home to work his deals stateside, he blames Max for Kyle's death, putting the dog in a whole new light to the family, particularly to Ray.