Doc and Emmie play outside while Emmie's mother is working on the Garden. Emmie kicks her leaky ball, which plops in front of the net. But she comments that it was all firm when she kicked it. Doc asks to try kicking it and she also notices the firm-ness of the ball. But Emmie tells her that since Doc almost scored a goal too, they need to keep playing! They can't just quit now, the championship is at stake. So when Emmie tries to kick the ball again, it makes it to the net!
Emmie then realizes that they won't be able to finish playing with a full ball and Doc decides to take it home to look over it. Emmie then tells her they can play again later and while Doc goes to fix it, she goes inside to get a Banana.
At her Clinic, Doc uses her stethoscope to bring the toys to life. She then introduces them to the leaky ball, Boomer. Though a few of them have already met him. He begins to ask why he can't plop after he tries to and bounced into the air. Doc then explains that they should give him a checkup in order to see if they can find the problem but Boomer begins to deny that anything is wrong. He instead tries to claim he is fine, to which Lambie asks if he's afraid of Doctor visits. With a bit of convincing and Boomer wanting to prove he isn't afraid, Doc is able to give him the checkup!
Soon Doc finds the problem, noticing that he is full of air. She deduces the problem right away. Doc points out that everyone has things inside of them. Boomer tries to leave again, but Doc tells him she'll have to deflate him, then he'll be almost better. She still need to put holes in him. Once again Boomer tries to escape!
This makes Doc realize that Boomer is afraid of needles. He's never had holes put into him before and needles are the one thing he is afraid of. But Doc tells him it is the only way they can make him leaky again, so that he can plop right. Suddenly, Chilly distracts everyone accidentally when he begins to panic and worry that he's running out of air. To which Doc has to remind him again that he is supposed to be squishy like that, since he is a stuffed snowman.
By the time everyone looks to Boomer again, he's already run away!
Before everyone rushes outside to find him, Doc assures them that because he is mostly inflated he couldn't have gotten too far. As everyone searches, Lambie manages to find him hiding out in a giant doll house! She tells him he cannot hide in there forever, but he refuses to come out. When Doc admits that she too is afraid of needles, Boomer is willing to listen and he asks her how she manages to deal with them. To which Doc admits that just being with her mom is enough to make her feel brave enough to handle a needle. Boomer admits that he does like hugs, and Lambie loves to hug people! Chilly also points out that they could all give Boomer a hug if he wants.
After they all sing a song, Boomer decides he will try to be brave so that he can get better and they pull out the needle Before Doc proceeds to use it, everyone begins to hug Boomer. The leaky process is done very quickly, but before Doc determines anything she checks Boomer's pressure once more. He seems to be leaking air!
Boomer then plops around the entire backyard while he sings the "I feel better" song and thanks Doc for her help. Stuffy asks if he's glad that he decided to be brave, to which Boomer happily confirms. Just then Emmie asks if Doc is ready to go play some more deflated soccer and the episode ends as Doc runs over back to Emmie's to resume playing!