Unknown to us how it happened, some of the steps to the City Hall broke. Luckily, Rubble fixes the steps on the double. Mayor Goodway is so impressed with him, she asks Ryder how he found him. He said that he was found in a tree. Mayor Goodway wants to know the story since she finds it strange to find a puppy in a tree.
As Ryder tells Mayor Goodway the story, we are sent into a flashback story to how the PAW Patrol met and rescued Rubble from a tree, and how he joined the PAW Patrol. The story starts with Marshall, Ryder, and Chase playing soccer in the yard until Marshall misses the ball and hits Rubble. Rubble is so amazed to see a ball that he plays with it, but the ball bounces into a tree. With great bravery, Rubble goes and gets the ball but gets stuck in the tree and becomes very scared.
Marshall sees Rubble and calls for help. Ryder and Chase hear Marshall's howls and arrive quickly, Chase wearing his pup-pack and uniform. When Ryder is unable to reach Rubble due to the ledge being too narrow, Chase uses his net to help Rubble climb to safety. Rubble admits to not being scared, then is offered something to eat by Ryder after he mentioned it. As the other pups watch Rubble eat, he reveals he's been on his own for a while, which made the pups feel sorry for him. He apparently hasn't eaten very much since the PAW Patrol found him, as he scarfs down the food like crazy.
As Rubble talks to the other pups about his past, Ryder gets a call from Jake. Jake has been trapped in some snow boulders up on Jake's Mountain and needs help. Ryder calls the pups, and as they head to the elevator, Marshall explains about the PAW Patrol to Rubble, along with his own skills as the PAW Patrol's firefighting pup, before he and Rubble crash into the elevator. As the pups are suited up, Rubble is amazed by what he sees, and is even more amazed upon reaching the top and seeing the inside of the Lookout.
As Ryder chooses Skye and Chase to assist with helping Jake, as they deploy, Rubble slides down the slide behind the others, and lands in the back of Chase's police truck. It is not long before Chase notices his passenger, tells Ryder, and has Rubble buckle up.
When they reach the mountain, Skye provides over watch, while Chase and Ryder try to figure out how to get down to Jake. During as they plan, Rubble spots a snowboarder, and wants to do it himself. Finding a spare snowboard and helmet, he's soon heading down to help Jake, after Ryder is rappelled down by Chase and his winch. Skye spots Rubble and tells Ryder, and when Rubble arrives, it doesn't take him long to dig right through the snow and reach Jake. Ryder is worried when Rubble disappears and asks Jake. When Jake reveals Rubble inside with him, and Ryder finds where Rubble dug a way out, he's impressed. Once Jake is rescued, he wonders if Rubble is the newest member of the PAW Patrol. This gives Ryder an idea...
Back at the Lookout, Ryder reveals he's found a home for Rubble. The other pups (especially Skye) are sad to see him go, until Ryder reveals Rubble's new home is with the PAW Patrol, much to Rubble's and the other pups' joy.
A little while later, Rubble is sworn in as the PAW Patrol's new Construction Pup, given his pup-tag and construction hardhat, and rides the slide down into his brand new digger/pup house. As the rest of the PAW Patrol join him, Ryder says he has some growing to do before he can reach the controls, but once he does, he will be a valued teammate to the PAW Patrol.
With that, the flashback ends, and Ryder sums it up as since that day, Rubble has been a good pup ever since. Rubble corrects him saying he's a great pup, and the episode ends with Mayor Goodway agreeing with Rubble as he gets another scratching from Ryder.