Chase's tooth gets loose, but he doesn't want to see the dentist because he is scared. Meanwhile, Alex must visit the dentist, but he's afraid too, so the pups and Ryder help him face his fear by showing him their own fears.
The episode begins with Chase, Rubble, and Zuma sniffing for buried items in the yard around the Lookout. Chase and Rubble each smell something, and competitively, each dig up one end of a stinky old tug toy. As they vie for pulling it out from their dig spot, Zuma joins Rubble to make it 2-against-1, winning the tug war and pulling the toy completely up from its bury spot. It is not long before Rubble and Chase start pulling on their ends of the toy, and while Zuma joins Rubble again, Marshall joins Chase to make it two-on-two. That is until Chase releases in shock due to a pain in his mouth, sending Marshall into a pile-up with the other pups. When Marshall asks what's wrong, Chase reveals that his puppy tooth is loose, giving him a lisp as he shows it's loose by wiggling it.
At Mr. Porter's, Alex seems scared of something, and his grandfather seems oblivious as he reminds Alex to get ready. As he is ready to start preparing to take Alex to the dentist for a checkup, Alex stops dead in his tracks at the mention of the dentist, and despite trying to show his grandfather his teeth are healthy, Mr. Porter goes to prep the van.
Back at the Lookout, Ryder soon learns of Chase's loose tooth, but like Alex, the mention of the dentist sends Chase whimpering, while cowering, back to his pup house in fright.
At Mr. Porter's, Alex has fled up into his tree house in an attempt to disguise himself, and when his grandfather tells him to come down, Alex purposefully unhinges several of the steps with a toy hammer, leading up to the tree house to trap himself up there. Alex thinks now it will take too long for his grandfather to find a ladder to get him down, and go to the dentist, but his spirits fall when his grandfather mentions calling the PAW Patrol to help.
Ryder is still trying to coax Chase into going to the dentist himself when Mr. Porter calls in regards to Alex. When Mr. Porter tries to show Ryder the situation with Alex, he ducks back into his tree house, out of sight, and even tries to tell both Ryder, and his grandfather, that he is okay not going to the dentist. Ryder assures Mr. Porter that they are on their way, but Alex tries to forestall seeing the dentist by asking Ryder not to hurry. No dice.
Ryder calls the pups, and after Marshall ties everyone up with the tug toy after getting the free end stuck in the entrance doors, causing it to snap back into Marshall and the others, they reach the top and get their orders:
Ryder will go with Marshall and Chase to rescue Alex, and then provide Alex a police escort to the dentist. The PAW Patrol deploy, and when they reach Mr. Porter's, Marshall gets right to work rescuing Alex. Alex is cowering in the corner of his treehouse, and when Marshall tries to coax him into coming down, Alex makes it clear he is not coming down, telling Marshall that he's scared of the dentist, and slamming the floor door shut in Marshall's face, leaving him confused. Seeing that he needs to talk to Alex boy-to-boy, Ryder offers to climb up and talk to Alex. Despite Ryder offering Alex a police escort from Chase to the dentist, he too gets the door slammed in his face when Alex agrees to the escort, but only to anywhere but the dentist. Not giving up, Ryder offers Alex a deal: If Ryder gets the PAW Patrol to show off what they are scared of, will that convince Alex to conquer his own fear? Alex shows interest in seeing what the pups are scared of, and Ryder agrees to call them to help out.
Once the rest of the pups show up, Ryder wonders which of them would be willing to show what they are scared of first. None of the pups seem too eager to volunteer, so Ryder goes first, revealing that while he goes into life-threatening situations every day with the pups, there is one thing that really gives him nightmares: Brussels sprouts, and he asks Mr. Porter to fetch some. As everyone watches, Ryder is able to somehow swallow one, much to Alex's amusement, but it is still not enough to convince Alex to come down. Ryder however, shows that he was able to conquer his fear, so now it's the pups' turn.
Rocky volunteers to go next, knowing it would be best to get his aquaphobia, or fear of water, out of the way first, and has Marshall hose him down. Next up is Rubble and his arachnophobia, or fear of spiders. After that, it is Marshall and Skye's turn, with Marshall's fear of flying and Skye's fear of eagles. During Rubble's turn of facing his fear, Alex has moved from inside his tree house to sitting on the top rungs of Marshall's ladder, enjoying the PAW Patrol facing their fears. When it is over, Alex is finally convinced to overcoming his own fear and going to the dentist, however, Ryder has one last job for Alex: Chase is also afraid of the dentist, but if Alex shows him how brave he can be, it can help Chase overcome his fear as well.
With that, Chase nervously escorts Alex and Mr. Porter in their van, with Ryder following behind, to the Adventure Bay Dentist's Office. Upon arrival, Chase gulps in worry, but Alex is able to convince him to go in together, much to everyone else's encouragement. Soon everyone waits, bored, for Alex and Chase to emerge. When they do, they each have a sticker from the dentist for their good behavior, and Alex even got a brand new toothbrush out of it! Chase shows that even though his puppy tooth has been removed, an adult tooth will grow in its place, and he can even whistle through where his tooth was.
Back at the Lookout, Chase wraps his tooth up in a cloth for the Tooth Fairy to collect. The next morning, Chase awakens the pups to reveal that the Tooth Fairy left him a brand-new bone for his tooth, but when he bites into it, another shot of pain occurs in his mouth, revealing another of his puppy teeth is now loose, ending the episode as the pups all laugh at Chase's luck in seeing the dentist, and having another tooth for the Tooth Fairy so soon after his last visit.