Usually when The Simpsons has a pair of plots, I can tell which is the main plot and which is the B-plot.
That’s not the case here.
Let’s cover them one at a time.
Homer comes in one day to find a rather tall woman named Roz has just been hired as his assistant. Roz is voiced by Jane Lynch, and sure seems friendly, until you remember she’s voiced by Jane Lynch and you know that ain’t gonna last.
Homer sneaks off work to see a movie preview for a Paul Blart sort of pile of crap with Barney and comes home happy to see Marge, but he’s still wearing the 3-D glasses so he can’t see Mr. Burns sitting next to Marge. Someone ratted Homer out! Now Roz will be his boss, not his assistant, and she isn’t nice at all, and Homer learns things like what a pay cut is. Roz is making Homer do all kinds of horrible and awful things, when a chance conversation with Ned Flanders reveals he too knew Roz from a church function. After she won a footrace, he gave her a congratulatory hug. She doesn’t like being touched.
As such, Homer comes out when Roz is winning an “employee of the millennium” award a bit prematurely and suggests Mr. Burns give her a hug. Roz sees what’s happening, but can’t stop Burns until after he hugs her. Then Roz rolls him up into a ball and tosses him through a basketball net. All Homer will say is he got the information from someone whose initials are “S.F.”
Yes, Roz does know that means Stupid Flanders.
Burns fires Roz and Homer gets his old job back.
Bart, meanwhile, needs an exhibit for the science fair. Lisa has something that proves the tow in doomed in a few thousand years from a meteor strike, but Bart sees Martin hanging from a tree by his underpants. Martin is good with ideas, so the two collaborate and come up with a robotic baby seal. Sure, it can be vicious if the wiring ain’t just right, but otherwise it’s cute and “aw”s win ribbons.
Bart and Martin do win, and while visiting Grampa at the Retirement Castle, the boy see the seal making gloomy Jasper happy again. The boys build a few more and bring joy to the retirement home. Then some funeral directors see business fall off from people not being miserable and dying and decide to do something about it by rewiring the seals to attack people. Not only do the seals do that, but they kill longtime resident Mrs. Glick!
However, Martin and Bart get help from some nerds including the renowned lady magnet Professor Frink to reprogram the robo-seals remotely while they sit in a holding cell. That works, though Frink’s insistence that they call their group the North American Man-Bot Love Association (NAMBLA), that doesn’t work as well.
Chief Wiggum won’t leave anything that cute locked up, and lets the seal go. He let’s Snake go for the same reason. The boys take the bots back to the Home. The residents start to dance with their seals to David Bowie’s “Golden Years”. Then the funeral people do the same. And then Mrs. Glick is seen dancing to it with Jesus in heaven.
Um, she might really be dead this time…