After watching the movie Doctor Dolittle at school, the children realize that Bart and Lisa smell badly and they start teasing them about it. The same thing happens to Homer at the nuclear plant, with Homer realizing (belatedly and angrily) that this is what people were referring to when they called him "Stink-son." Marge then discovers that the smell is coming from their clothes because their washing machine is old and covered in mold. She then gives Homer a bag full of money (derived from Bender's body, which has been in their basement since the events of "Simpsorama") so they can buy a new washing machine. On his way to the store, Homer smells something delicious and discovers a roadside barbecue stand run by an old biker. When Homer eats the best BBQ he's ever had, the biker reveals that the secret is that the smoker was made from a meteorite with a unique beehive shape that has trapped all of the fat and sauce from every grilling ever. Homer weighs up whether to do what he should do (buy the washer) or what everyone knows he will; he passes up the washing machine to buy the smoker for himself.
Marge gets upset that Homer spent all their money on a "grill" but forgives him and joins the family for a barbecue when she eats the food herself (Lisa eats a barbecued carrot). The aroma draws people from all over Springfield to the Simpsons' backyard to feast on savory cuts of meat. Eventually, Homer's grill becomes so popular that "Chew Network" chef, Scotty Boom, shows up and contemptuously challenges him to a smoke-off.
Whilst preparing smoked pork to take to the competition, Homer discovers that his smoker has been stolen. He calls the police, but Clancy and Lou convince Homer that his smoker is gone and will never be found. However, Bart and Lisa decide to investigate the crime themselves when they notice Homer is so distraught over the theft that he is even refusing to get drunk. They investigate the yard and discover that the thief gave Santa's Little Helper a jar of natural peanut butter to distract him, so he would not bark. The duo then proceed to the one store in town that sells natural peanut butter, where they use some violence to "convince" a worker to let them see the security camera footage, which shows Nelson purchasing the peanut butter.
Bart and Lisa go talk to Nelson in a park, where he's playing a tablet game called "Clash of Castles" with some expensive upgrades. Nelson is reticent and runs towards a scrap yard to meet someone shortly afterwards, where the duo observe him being paid and revealing the smoker under some trees. Nelson leaves the smoker behind, but it's too hot for Bart and Lisa to walk it back and it ends up being loaded onto the truck and driven away.
Homer, Bart, Lisa and Maggie give up hope on the competition, but Marge convinces them that she can handle the smoke-off with the help of a rented spice rack. At the competition, hosted by Alton Brown, Marge does her best against Scotty Boom but fails miserably because she used all of the spices together. However, when Scotty presents his meat, it is discovered that the hive shaped grill marks on it do not match his normal grill and he is accused of cheating. Scotty is fired from the "Chew Network," banned from the competition, and arrested by Chief Wiggum. The Simpsons are then proclaimed winners.
This does not fully satisfy Bart and Lisa, who try to find out why the smoker was stolen on the first place. Soon, they hear the same cellphone ringtone they heard when Nelson was delivering the smoker and so they decide to chase the phone's owner down. When they catch him up, they discover that he is Scotty's son, Tyler Boom, who framed his father because he was too busy with his TV show and didn't spend any time with his family. Tyler explains that he met Nelson playing "Clash of Castles" and hired him to steal Homer's smoker in order to frame him. Scotty and Tyler soon reconcile, everything is cleared up with the authorities and Tyler gives Homer's smoker back.
During the end credits, several scenes show the future of the Hive Smoker, starting with the Simpsons trading it to Nelson for a new washing machine, and ending with alien bee people taking the hive back into space.