The PAW Patrol is just about to zoom off on their latest rescue to help Farmer Al capture his runaway pigs, Emma and Corny, when Chase sneezes, then Zuma sneezes and in a blink of an eye, Skye joins the group of sick puppies. EMT Marshall has his hands full - duck your head and the germs won't spread! Only Rocky and Rubble are well enough to join Ryder at Farmer Al's. Luckily, Alex is there and he is ready to help make repairs and get the pigs back in the pen.
The episode opens with Chase and Zuma about to race against each other: they are lined up and waiting for Rocky's signal. When Rocky says "Go!" he launches a tennis ball into the air using his catapult and Chase and Zuma give chase. Both pups call the ball as theirs, and as they pass by, Rubble and Marshall are seen playing tug-of-war. Just as Chase is about to get the ball, he sneezes the ball away. Disgusted, Zuma declares the ball as Chase's. Chase excuses himself and reasons that his allergies must have caused him to sneeze; then he sneezes again.
Over at Farmer Al's farm, Farmer Al and Alex try to keep a dirty Emma and Corny still. Failing to do so, Farmer Al gets Alex to get some of Farmer Yumi's cornbread. Alex comes back with two pieces, and is asked to toss one near Emma and Corny. As the pigs eat, one of Farmer Al's geese steals the other piece of cornbread from Alex's hand. The goose continues forward and steals Emma's and Corny's piece as well; scaring the pigs in the process. In a panic, Emma and Corny break through a section of fence and run toward the woods. Farmer Al and Alex chase them, with Farmer Al even getting his hands on Corny, however the pigs are too fast and slippery for them. Corny even snorts in laughter over being able to escape before he runs after Emma and into the woods. Knowing that they need help, Alex calls Ryder.
Ryder slides out from under his ATV to answer the call. Alex and Farmer Al explain the situation, and Farmer Al expresses his concern that Emma and Corny may fall into the creek. Ryder naturally summons the PAW Patrol. Rubble accidentally lets go of the tug-of-war toy, causing Marshall to fly backward and get his feet tangled in it. On their way to the Lookout, Marshall trips and Rubble gets tangled along with him. They crash into the center of the elevator, with Marshall joking that the race must have ended in a hogtie.
In the Lookout, Ryder relays Farmer Al's problem to the pups. He calls on Rocky to repair the fence and Chase to round up the pigs. Just before Chase can say he's on the case, however, he sneezes repeatedly. Marshall steps in and Chase again claims it's his allergies, but Marshall gives him a thermometer to put in his mouth. Chase sneezes it out almost immediately, and Marshall states that he has a cold. Chase whines, and Ryder says that Chase must stay at the Lookout and take care of himself. Next, Ryder calls on Zuma to rescue the pigs if they do end up in the creek. Before Zuma can finish answering, he also sneezes. Marshall gives him a thermometer and confirms that Zuma has a cold as well. Marshall is told to stay and take care of the sickly pups, and Ryder says that he will try to get Katie to aid him. Ryder then calls on Skye to search for the pigs from the air, but mid-flip Skye sneezes as well, sending her flying backward. Skye is assumed sick and guesses that she has to remain at the Lookout also. With half of the pups out of action due to illness, Rubble steps up to join the mission, claiming that he feels fine and is ready to help, so Ryder agrees to bring him on the mission. As Ryder runs past the pups to get prepared, some cough and sneeze.
Arriving at the farm, Ryder asks Rubble to see if he can sniff out Emma and Corny. Alex states that he is also there to help and shows everyone his own homemade PAW Patrol backpack. He barks and calls for his tool arm, but the hammer breaks off when it opens, much to Alex's embarrassment. Rocky is asked to fix the fence, so he finds a wooden board and uses his ratchet to screw it in place. Ryder goes to get a second wooden board. In the meantime, Alex is eager to help in any way possible, so Rocky asks him to fetch him a bowl of water since his throat is "scratchy." Alex runs off to do so, and Ryder returns with another piece, which is promptly put in by Rocky. After placing the second board, Rocky sneezes. Ryder immediately knows he's sick as well and calls for Marshall.
Back at the Lookout, Katie has made chicken soup for everyone. Marshall receives a call from Ryder asking Marshall to come help Rocky. Marshall soon arrives at the farm with his ambulance. When he goes over to Rocky, Rocky accidentally sneezes in his face, and Marshall prescribes Rocky with liquids and rest. Rocky also sounds like he might have a stuffy nose as well. Rocky thanks Marshall, but worries about who is going to finish fixing the fence. Alex shows that he finished gluing the third and final wooden board (which also has screws in it), in place, while also gluing a piece of the broken fence to his bottom. Alex is complimented and helped out by Ryder, while Rocky is loaded into the back of the ambulance and told he has chicken soup waiting for him.
With the fence fixed, Rocky is transported back home to the Lookout by Marshall, and Ryder prepares to go search for Emma and Corny. He finds Rubble and asks if he's had any luck; Rubble calls "Sue" multiple times and Emma comes running back. With Rubble chasing Emma, Alex deploys a miniature version of Chase's net, which lands on Emma's face. Emma stops, flicks it away, and continues running, with Ryder narrowly failing to catch her. Corny then comes back and follows Emma.
The group again gives pursuit to the pigs, but even Ryder is out of breath and comments on the pigs' speed (Rubble keeps chasing and calling "Sue"). Farmer Al stops and expresses that he's relieved that the pigs are away from the creek now, and states that Emma and Corny usually return to the barn when they're hungry. Ryder suggests offering them a treat to hurry them up, and Alex rushes off to open the silo. Before Farmer Al can finish his warning, Alex opens the bottom door and a mass of corn cobs fall out. Emma and Corny go to eat the corn, and Farmer Al trips over the cobs as he tries to stop them from eating too much. Later on, corn is placed in front of the pigs, and Rubble easily carries them into their pen using his bulldozer.
Back at the Lookout, Ryder is greeted by Marshall, who is about to claim that everyone who is sick are recovering well before he sneezes, making it clear he's come down with the same cold, but thanks to his medical expertise, he's ready for it. Marshall then instructs everyone to go to bed and how to avoid spreading the germs, and demonstrates it himself. The episode closes with Ryder saying that they're all good pups, followed by him sneezing, but taking Marshall's advice to cover their mouths when they do.
Note: All of the other pups were attempted to be summoned, but were unable to follow through due to being sick. Rubble was the only one alongside Rocky to actually go on the mission, despite not being officially called upon.