Riot is an Australian Shepherd. The dog at one point was hit by the Impala. Sam, realizing this, rushes the dog to the veterinary hospital, where the dog gets treated by a vet named Amelia. Sam later accepts his responsibility for the dog, and agrees to take care of him. It is now assumed, after Sam left Amelia, that she is now the caretaker of Riot.
Sam is in a house in Kermit, Texas. As Sam leaves he pets Riot, who is on the bed where Amelia lies, pretending to be asleep. Outside a mysterious figure watches the house.
Sam remembers when he hit Riot with the Impala. He rushed him to a veterinary hospital, where Amelia is the vet who tends him. Riot sustains some serious internal bleeding and at least two leg fractures. Amelia tells Sam the dog has no owners, and points out his responsibility for the dog, and so Sam agrees to take care of him.
Sam remembers being in a park with Riot, looking for Amelia. Riot runs off, and when he follows him, Sam finds Amelia waiting with a birthday picnic.
Sam remembers how Riot, who he doesn't yet have a name for and just calls "Dog," leads him into Amelia's motel room, which he doesn't want as she thinks he's creepy. However, Amelia calmly pets Riot and they discuss how Riot is recovering well and Sam compliments how skillfully she stitched him up.
Riot appears in Sam's flashback when Amelia's father comes for a visit.
Sam is seen playing fetch with Riot in a flashback where he and Amelia are speaking about Don.
Riot appears in Sam's memory hole.