The "Bones" episode "The Method to the Madness" opens with a garbage truck driver on his route, singing opera at full volume. He manages to convince his partner to start singing along with him, but their song soon turns to screaming. The garbage being dumped into their truck includes a rotting human corpse.
Elsewhere, Sweets is still mopey after breaking up with Daisy. He has been sleeping in his office for two weeks. In an attempt to cheer his spirits, Booth offers Sweets a room at his house for a few days while he gets his life together.
Bones examines the body and determines it was a female in her early to mid-20s, who had muscles ripped off her bones. Hodgins can tell from the bug life on the body that she died 36 hours ago. Hodgins also finds a plastic bag that contains the guts from the woman's body... but then the bag starts to leak.
Back at the lab, Angela is having a hard time. Not only does the victim's facial reconstruction pose a problem because of the extensive damage to the body, but also because she appears to be having another crisis about whether she is a good fit for this kind of work.
It turns out that the killer was smart and used ammonium hydroxide (a common anti-bacterial agent used in food prep) to remove any bits of trace evidence from the body. However, after a bit of computer wizardry, both Hodgins and Angela instantly recognize the victim: It's the lady that makes their artisan applesauce.
Booth and Brennan visit a part of the city where every business seems to be some kind of artisanal food shop. Their investigation reveals that the applesauce girl was also up to another kind of business: the oldest profession in the world.
There are a whole range of suspects, from the local, knife-happy butcher to the victim's kinky sex partner. But the real culprit is revealed thanks to Angela's sharp eyes. Angela notices that the corpse appeared to have been hacked in a specific pattern -- a pattern that was caused by an industrial machine of some kind.
The victim was killed by her applesauce business partner, who slapped her during a fight. The victim wanted to sell out of the business, and her partner was having none of it. The slap sent the vic rolling into the applesauce machine, where she died. Case closed.