The episode opens with the scientist guy explaining that the vocabulary words are going to be about law and order, but a woman next to him keeps saying, "Shh!". We then see Helen and TD outside a restaurant (with Martha nearby), arguing over whether he took her French fry. She tricks him into admitting he took it by pretending he has a piece of French fry stuck between his teeth. Then, Alice shows up and invites the two to her birthday party, but Helen and T.D. seem worried about this aspect.
The scientist explains why the two are worried — it's because Alice is very clumsy and as such, her birthday parties tend to go wrong. After three flashbacks to disastrous birthdays, Alice explains that it's a costume party and everyone must dress as their favorite invention. She then invites Martha as well, which excites her since she's never been to a party before.
Helen (dressed as a paint set) and Martha (dressed as a pet door) arrive at the party, but Martha has second thoughts when she realizes it's at the Boxwoods' since she and Nelson have beef. Helen brushes Martha off, and the party starts (with Alice dressed as a parachute, Carolina as lipstick, TD as a sausage, and Truman as a jar of medicine). Mrs. Boxwood has made her own kind of (unpleasantly sour) lemonade, while Mr. Boxwood has hired a robot clown. Alice wants to play Pin the Tail on the Donkey, but her friends don't trust her with pins, so Martha has them play a similar blindfolded game called Give the Dog a Biscuit, which is just what it sounds like.
Afterwards, Nelson asks Martha (in meows) to prove she can pick up a rock, which she does, then he asks her to pick him up. But when she does, the humans accuse her of biting Nelson and Helen locks her in the garage as punishment. The kids try to play with a digital pinata, but then Mrs. Boxwood cries, "Oh no!". They rush to her to find that somebody has eaten part of Alice's cake.
Truman determines it was an animal that ate it, so Ronald checks on Martha, who has cake crumbs in front of her. However, when he accuses her of eating the cake, Martha doesn't even know about the cake. Thus, Ronald decides to put her "on trial". He wants to be the judge, but Alice doesn't let him, accusing him of bias, and has Truman be the judge instead.
Truman starts the trial and asks Ronald for evidence, but he just disses dogs. When Truman says that evidence is about fact, not opinion, he points out the crumbs. He then describes it as an "Open-and-Shut Case", making T.D. realize that the garage door was shut. Then, he adds that since Martha is such a Big Eater, she wouldn't just leave the crumbs lying around. He suspects Nelson of being the culprit, but Ronald then points out that this doesn't make sense, since he can't open doors. T.D. thinks Nelson snuck through the vents and dumped the crumbs in front of Martha while suspended on a wire.
Then, Nelson throws up and is found guilty when a birthday candle is seen in the puke. Mrs. Boxwood and Ronald take Nelson to the vet and the trial is closed. They still don't know how the crumbs got near Martha, but a zipline is shown... yet it's still unsure how Nelson could have used it since he doesn't have hands. Meanwhile, the vet has trouble examining Nelson.
This episode provides examples of
- Air-Vent Passageway: Discussed when T.D. wonders if Nelson snuck through the air vent.
- Ambiguous Ending: We still don't know how the crumbs ended up in front of Martha, and a zipline is seen. If Nelson did use the zipline, then how was he able to use it without any hands yet still be unable to open the door? If he didn't use it, then where did it come from and how did the crumbs end up in front of Martha?
- Baby Talk: Ronald talks in a sappy, affectionate way to Nelson when he feels sorry for him.
- Birthday Episode: This episode centers around Alice's tenth birthday party.
- Birthday Party Goes Wrong: Because of how clumsy Alice is, her birthday parties tend to go wrong:
- On her second birthday, she fell face-first into the cake.
- On her eighth birthday, she accidentally threw a scoop of ice cream down T.D.'s shirt and he knocked a chocolate fountain over while squirming, causing a waiter to slip on it and send ice cream flying onto everyone.
- On her ninth birthday party, she accidentally jams up a water wheel with a golf ball and sends it rolling.
- Zigzagged for her tenth birthday. Part of her cake gets eaten, spoiling the cake. Martha and Nelson are both suspected, then Nelson gets nauseous and has to be taken to the vet, but Martha's name is cleared. Mrs. Boxwood buys a second cake, but Alice accidentally smashes it.
- The Cuckoolander Was Right: Implied, in the end, as the zipline from TD's theory appears through the garage window.
- Death Glare: Helen and Alice give Carolina dirty looks for finding Nelson cute.
- Early Personality Signs: Alice has been a klutz even since she was two, when she fell face-first into her birthday cake.
- Easily Condemned: Martha is first quickly accused of hurting Nelson by the humans and put in the garage after Helen refuses to hear her out. Then she gets further accused by Ronald for eating Alice's cake.
- Episode Tagline: Carolina repeats, "I'm hungry" several times.
- Fake Alibi: Someone took a big bite out of Alice's birthday cake and left crumbs next to a sleeping Martha. Nelson, a cat, is supposedly cleared since he doesn't have hands and thus couldn't open the door to the basement where Martha was. As it turns out, however, he did do it. How is still a mystery, although it's implied at the end that he may have accessed the basement via a zip line.
- Flashback: When the scientist is explaining how Alice tends to mess up her birthday parties, we see footage of her second, eighth, and ninth birthday parties.
- Food Coma: Discussed when Helen says to Martha, "You ate a lot of biscuits; why don't you take a nap?"
- Grumpy Old Man: Or in this case, woman — at the beginning, an old woman in the library keeps frowning at the scientist and shushing him, then says, "Give that back, you hoodlum!" and snatches his magnifying glass.
- Hairball Humor: Exploited. Nelson is found guilty when there is a birthday candle in his hairball.
- Layman's Terms: Truman says that Martha is "exonerated" of all crimes. She doesn't know what that means, so he explains that she's innocent.
- Lost My Appetite: Carolina ceases to be hungry when Nelson throws up.
- Mystery Episode: The episode is about trying to determine whether it was Martha or Nelson who ate the cake — it turns out to have been Nelson framing Martha, though how he did it is left unclear. Although, it's implied in the end that TD might have been a little bit right when the zipline from his theory appeared at the end.
- Oh, Crap!:
- Knowing how clumsy Alice is, Helen and TD make wild takes when she invites them to her birthday party, since her parties tend to go wrong.
- When Martha says, "You try putting a whole cat in your mouth!", the humans frown at her, causing her to say back nervously, "This doesn't sound good, does it?".
- Puppy-Dog Eyes: When Nelson is trying to look too cute to be guilty, he makes large eyes.
- Same Clothes, Different Year: Zigzagged.
- When Helen and T.D. were two and Ronald was seven, they still wore the same outfits (though Alice wore a different outfit then).
- When Helen, Alice, T.D., and Truman were eight, and Ronald was thirteen, most of them wore different clothes, but Truman wore the same clothes.
- Say My Name: Ronald shouts, "Nelson!" when the latter throws up.
- Skewed Priorities: Carolina is more concerned about being hungry than about who ate the cake.
- Sophisticated as Hell: The scientist explains that "in scientific terminology, Alice Boxwood is what's known as a ginormous klutz."
- Speak in Unison:
- Just before being splattered with ice cream two years ago, the Boxwood siblings and Alice's friends say, "Uh-oh!" in unison.
- When Truman asks if the jury has reached a verdict, they say, "Not guilty!" in unison.
- When Martha wonders if Nelson did put the crumbs near her, Helen, T.D., and Alice say, "Nah!" in unison.
- Stink Snub: Ronald accuses dogs of stinking, much to Martha's displeasure.
- Tempting Fate:
- In the flashback to Alice's last birthday, the water wheel gets jammed, and T.D. says, "Could have been worse". Seconds later, the wheel comes loose and rolls towards them.
- Ronald says that there were only ten candles on the birthday cake since Alice is ten years old and there were nine left over, so Nelson can't have swallowed another... only for Nelson to cough up a second candle, that was there "to grow on".
- Vomit Discretion Shot: Nelson is offscreen when he coughs up the cake and candle, then again when he coughs up another candle.
- Why Did It Have to Be Snakes?: TD is implied to be afraid of clowns when he describes the robot clown as "scarier than a real clown".
- Wounded Gazelle Gambit: Nelson tricks Martha into trying to pick him up so that it'd look like she bit him and she'd get into trouble.
