After Martha explains that the vocabulary words are about mysteries, Helen and her dogs go to the zoo. However, the animals are louder than usual and Martha reveals that they're unhappy and are mentioning a "mystery". She asks a lemur what's going on, and the lemur reveals that someone's been stealing the zoo's peanuts at night and Jeffy (the zoo's elephant) is the prime suspect.
Martha goes to Jeffy to hear his side of the story, and he claims that he didn't take the peanuts. Martha asks him to tell her what happened last night, but the zookeeper interrupts and explains that every afternoon when he closes the zoo, he puts the peanuts away, but they're always gone the next morning. Helen asks the zookeeper why he thinks Jeffy did it, and he explains that a bag of peanuts was seen near Jeffy's enclosure and Jeffy is the only one who can eat that much food.
That night, Helen tries to do her homework, but is distracted by her dogs, who are pacing around the kitchen and contemplating the zoo situation. The dogs then decide to go to the zoo to interrogate the animals. Martha questions a tiger cub, who claims she saw something large and grey leave the storage room. Then, the lemur claims he saw an elephant-shaped shadow drag the peanuts, and one of the penguins claims he saw an elephant drag peanuts to Jeffy's enclosure.
Martha is confused, since Jeffy is the only elephant at the zoo, but then she sees a robot elephant. She thinks the robot is the real thief, and is proven correct when it takes a bag of peanuts. Then, the robot leaves a trail of peanuts to Jeffy's enclosure to frame him. The robot is then put in a truck, but it drives away too fast for the dogs to follow it.
Luckily, they find the truck parked outside Weaselgraft and Pablum's hideout. Inside the hideout, Weaselgraft and Pablum plan to move the peanuts out, which is bad news since without the peanuts, they can't prove Jeffy's innocence, and trying to stop Weaselgraft and Pablum would take too long.
The dogs go back to the zoo and summon the lemur, a bat, one of the penguins, the tiger cub (named Tiger Baby), and Jeffy. The bat finds a broken window, then the penguin distracts Weaselgraft and Pablum by dancing at the door. Meanwhile, the bat and lemur go in through the window and let the rest of them through the other door (except Jeffy, who is too big). Martha and Skits find the door where the peanuts are kept, but the lemur can't open it.
Luckily, Martha and Skits can eventually open it by pawing at the handles, but by then, Weaselgraft and Pablum have grown bored of watching the penguin, and they enter the scene. Martha asks the villains why they stole the zoo's peanuts, and Weaselgraft explains that he recently won the lottery, but Pablum spent all the money on the robot, so they're planning on selling them at baseball games. However, they are trapped by Tiger Baby at the front door (scaring them since apparently they're scared of baby animals) and Jeffy blocking the back door.
Back at the zoo, Danny and Helen show up looking for Martha and Skits, who have returned the peanuts and made Weaselgraft and Pablum dance in the penguin enclosure. Danny then plans on calling the police.
This episode provides examples of
- Accessory-Wearing Cartoon Animal:
- Martha wears a wig when popping out of the dress-up box.
- The penguin puts on a hat to distract the bad guys.
- Absurd Phobia: Weaselgraft and Pablum apparently are afraid of baby animals.
- Agony of the Feet: The robot elephant steps on Weaselgraft's foot twice.
- Clear Their Name: Martha and, to an extent, Skits and some of the other zoo animals, works to prove that Jeffy didn't really steal the zoo's peanuts.
- Comically Missing the Point:
- When Weaselgraft complains about Pablum spending all of the lottery money on a robot elephant, Pablum says, "It's solar-powered."Weaselgraft: "I'm not upset about WASTING ENERGY!"
- Weaselgraft and Pablum fear Tiger Baby, not because she's a predator, but because they're afraid of baby animals.
- When Weaselgraft complains about Pablum spending all of the lottery money on a robot elephant, Pablum says, "It's solar-powered."
- Cool and Unusual Punishment: The animals punish Weaselgraft and Pablum by making them dance for the penguins.
- Evil Laugh: Weaselgraft and Pablum laugh evilly at the idea of illegally watching baseball games for free.
- Flashback:
- When the zookeeper explains how the peanuts disappear, we see it happening.
- We see the past when Weaselgraft explains why he and Pablum stole the peanuts.
- Frame-Up: The robot leaves a trail of peanuts near Jeffy's enclosure so it looks as though Jeffy took them.
- A Dog Named "Dog": According to Martha, the tiger cub is named Tiger Baby.
- Hurt Foot Hop: Weaselgraft hops after the robot elephant stands on his foot.
- Ice-Cream Koan: Martha was apparently given the advice "If you need answers, the first thing you should do is ask the nearest lemur".
- Mistaken for Thief: The zookeeper and most of the animals think Jeffy took the peanuts, but it was actually a robot built by Weaselgraft and Pablum to frame him.
- Mystery Episode: The main plot of the episode is Helen's dogs trying to determine who stole the zoo's peanuts.
- Race-Name Basis: Martha addresses the lemur simply as "lemur" due to not knowing its name.
- Speak in Unison: Upon seeing Tiger Baby, Weaselgraft says, "Nothing in the world frightens us more than..." then he and Pablum shout, "Babies!".
- Stock Animal Diet: Played with. Jeffy, an elephant, is suspected for stealing peanuts, but the zookeeper doesn't suspect him just because he's an elephant — he saw a bag of peanuts by Jeffy's enclosure and Jeffy is the only one who could eat that much food.
- Voodoo Shark: After solving the mystery of who stole the peanuts (the robot elephant), Martha then points out that there's a second mystery — why would a robot want peanuts?
