The ninth episode of the eighth season of Rugrats (1991).
Mysteries abound when the babies and their parents take an overnight train trip to Little Biendeltown for Boris and Minka's second honeymoon. Wawa, Cynthia, and Minka's necklace have all gone missing, and the babies try to solve the mystery of who the thief is.
This episode provides examples of:
- Companion Cube: Chuckie and Angelica both bring their favorite toys on the train trip, Wawa for the former, and Cynthia for the latter.
- Determinator: Tommy. When Wawa gets stolen, Tommy is determined to help Chuckie get him back even when the other babies are ready to give up.
- "Eureka!" Moment: When Tommy finds Cynthia hidden underneath one of the seats, he comes to the conclusion that Angelica must have taken Wawa by mistake when they went through the tunnel.
- Gilligan Cut: This is done with Chuckie who is quite scared while he and the rest of the cast are riding on a train, although this one ends on a more positive note...Kimi: It's just a choo-choo, Chuckie.
Chuckie: This ain't no choo-choo! It's a big scary train! I don't like it and I never will!
[cut to Chuckie enjoying eating ice cream in the train's dining car] - Here We Go Again!: The episode ends with the babies screaming as the train goes through a tunnel on its way back home.
- Hypocritical Humor: Angelica chides Chuckie for bringing Wawa with him, but Lil points out to her that she also brought a toy with her, in the form of her Cynthia doll. Angelica insists that Cynthia is not a toy, but rather a traveling companion.
- Immediate Self-Contradiction: After the babies find Cynthia and are about to sneak out to see if Angelica has Wawa, Lou shows up and tells them he's watching them like a hawk so they can't get away. He falls asleep immediately afterwards.
- Mystery Episode: In this episode, Wawa goes missing during a train ride, and the babies have to find out who took him.
- Never My Fault: When Drew and Stu get locked outside the brake coach, Drew blames Stu for it even though he dared Stu to sneak out and have some fun.
- Old Flame: Dwayne Tickerbacker, Lulu's ex-boyfriend boards the train, and Lou is not happy to see him when he tries to impress Lulu, given that Lulu is his wife now. Lou even calls the trope by its name.
- Potty Emergency: One little girl does this outside the bathroom door when Charlotte is revealed to be hiding in the bathroom to get some work done in private.
- Rule of Three: Didi and Kira try to identify three several landmarks the train passes on their trip, but something happens that results in them missing all three of them. First, they miss Vegetable Rock when Dil spits up, then they miss Cough Drop Pass when the detectives take them away to ask them some questions about the robbery. Finally, they miss the love geysers when black smoke emits from the engine due to the babies playing there.
- Scary Shadow Fakeout: When Tommy sees Jonathan's shadow, Jonathan holding his cell phone makes it look like he's holding Wawa.
- Senior Sleep-Cycle: Lou, as usual. When Didi tasks him with looking after the babies, he falls asleep, allowing them to escape and chase down the mysterious stranger. When Didi comes by to check on them, Lou tells her, "Sleepin'!", which makes her think he meant that the babies are sleeping. After the babies find Cynthia near the end of the episode and are about to leave, Lou tells them he's watching them like a hawk so they won't be able to get away... then falls asleep immediately afterwards.
- Shout-Out: This episode's title is a reference to Murder on the Orient Express.
- Thriller on the Express: In this episode, the Pickles, Finster, DeVille and Kropotkin families go on a scenic train ride to a historic tourist town for Boris and Minka's second honeymoon, complete with a 1930s-style streamlined steam locomotive pulling the train. As the train goes through a tunnel, several things go missing; Minka's necklace, Wawa, and Cynthia. Tommy and Chuckie suspect a tall, dark stranger in a conspicuous trenchcoat who snuck aboard the train of being the thief. In the end, it is revealed that Jonathan was the stranger who came along with Charlotte to help her get her work done faster, Dwayne Tickerbacker had stolen the necklace, Cynthia ended up under a seat in the babies' compartment, and Angelica accidentally grabbed Wawa in the dark, thinking he was Cynthia.
- Train Job: A notorious train robber is on the loose, and the parents are worried that the robber has boarded their train, especially when Minka's necklace goes missing. At first, all signs point to a mysterious man in a trenchcoat being the thief, but when the babies chase him down, suspecting that he stole Wawa, he is revealed to be Jonathan, who snuck onboard the train to help Charlotte get her work done. Some detectives board the train and investigate, eventually finding out that Dwayne was the thief, as Minka's necklace is in his possession.
- Train-Station Goodbye: Angelica and Brett have one at the end of the episode, when Brett stays in Little Biendeltown due to it being his home. Angelica is sad to have to say goodbye to Brett at first, but then remembers that because of him, she was forced to be nice to the babies.
- Trouser Space: Tommy stashes Howard's belt in his diaper after using it to open the doors on the train.
- Villain with Good Publicity: Dwayne, who is revealed to be the thief at the end, is very polite and well-liked by the other passengers, except for Lou, who doesn't trust him.
- Wardrobe Malfunction: The babies take Howard's belt and use it to open the door so they can escape and chase down the mysterious stranger. When the adults awaken and find the babies missing, Howard's pants fall down, exposing his underwear.
- Why Did It Have to Be Snakes?: Stu is none too enthusiastic about riding on a real train, presumably because he was nearly run over by the train from the North of the Border theme park in a previous episode, "Where's Grandpa?". He's even shown hiding behind a newspaper he's reading when he sees Chuckie playing with his toy train at the beginning of the episode.
