Martha is excited to learn that Grimble's, the department store, is giving out free samples, but annoyed to learn that it isn't food. Instead, it's perfume, which Martha dislikes. A woman recoils at the smell of Martha, causing Helen to declare that it's bath time, but Martha Hates Baths. She thinks she and Skits could wear perfume instead.
She goes to T.D. (having Helen follow her) and asks him to have O.G. invent a dog perfume. T.D. thinks this is impossible, but O.G. thinks that it would be good for the environment if dogs never bathed. He goes into the garage and starts musing about different types of perfumes. She wants a bacon-flavoured perfume, so O.G. decides to consider it.
On the sidewalk, Helen explains to Martha that perfumes are made up of several components, not just one, while T.D. notices that Martha does indeed smell bad. Helen and T.D. take Martha to Mariella's work, and she gives them flowers. Helen asks Martha if she likes their smell, and she is apathetic about it, but likes the smell of the trash. She then knocks the can over and gets trash on T.D.
He takes a bath, then Martha promises to let him wear the perfume too to apologise. Then, Helen, T.D., and Martha go into the woods to forage for ingredients. Martha thinks they should use mud in the perfume and begins rolling in it. Then, she shakes it off on him, leading to him needing another bath. Helen offers Martha some citrus peel, and she thinks they smell okay but a dirty shoe smells better.
In the garage, Helen and T.D. start sorting the ingredients they collected so that O.G. can extract their scents. Then, once he's done that, Helen and T.D. begin trying different combinations of perfumes and seeing which ones smell good and which don't. Then, they see if Martha likes the perfumes, but she's too picky, and T.D. gives up. Luckily, O.G. finally creates a perfume Martha likes, which smells of bacon to a dog but is odourless to a human. This works in making Martha no longer stink, but it creates unwanted attention from other dogs, so Martha decides she wants a bath after all.
Helen, Martha, and T.D. then go to the cafe and eat some yogurt, then go off to watch TV... but not before a woman sprays herself with the bacon perfume and is chased away by dogs.
This episode provides examples of
- Amusing Injuries: In one of O.G.'s diagrams, a woodpecker pecks her on the head.
- Bait-and-Switch: O.G. appears to be working on the dog perfume, but he turns out to instead be making pea soup for lunch... with his lab equipment.
- Bee Afraid: One of O.G.'s drawings has a bee charging at her with its stinger poking out.
- Buffy Speak: O.G. uses the term "citrus-y" to describe the scent of citrus fruits.
- Comically Missing the Point: When the illustration of Martha croaks, "Water!" after eating a hot pepper, Helen and T.D. drench her in water instead of giving it to her to drink.
- Death Glare: T.D. glares at Helen for spilling green liquid on him.
- Fantasy Sequence: Martha imagines herself and Skits wearing perfume to avoid bathing.
- Filthy Fun: Martha rolls in a mud puddle in the woods.
- Fire-Breathing Diner: In one of O.G.'s drawings, Martha breathes fire after eating a chilli pepper.
- Hates Baths: In addition to Martha's usual hatred of baths driving the plot, T.D. is annoyed when he has to take one and is keen to wear the perfume that means he'll never need to bathe.
- I've Heard of That — What Is It?: When O.G. explains that you need to extract scents to make perfume, she says, "Extract? You're gonna extract? I love to extract! What's extracting?".
- Kids Hate Vegetables: Helen and T.D. (who are both ten years old) both cringe when offered pea soup.
- Pun-Based Title: The title puns on "sense" and "scents".
- Visible Odor:
- In Martha's imagination, she and Skits appear to emit steam when they smell bad.
- When O.G. draws the unwashed Martha, he draws her with stink waves.
- When Martha smells the trash and the mud, the smell is drawn like steam.
- Helen's green perfume emits a green smell cloud.
- Running Gag: T.D. keeps getting dirty and needing to take a bath.
- Slapstick: Martha keeps accidentally splattering filth on T.D., and then Helen does.
- Smelly Feet Gag: Martha likes the smell of a dirty shoe and wants that to be a perfume ingredient.
- Stock "Yuck!": In addition to the Kids Hate Vegetables moment, T.D. gives fish stew as an example of something that smells bad.
- Take Our Word for It:
- We're told that Martha stinks badly in this episode, but the smell is never described apart from being very bad.
- One of the perfumes Helen and T.D. made is said to smell very bad, but its smell is also not described.
- Technicolor Science: Subverted — O.G. pours green liquid into his beaker... which turns out to be pea soup.
- You No Take Candle: When the Martha in the illustration eats a hot pepper, she's only able to croak out the word "water".
