The second season enters the home stretch with two different kinds of mysteries.
Season 2, Episode 24: "MMMystery on the Friendship Express"
So, MMMM: Marzipan Mascarpone Meringue Madness.
It's the perfect cake-storm of meringue's smooth, silky sweetness combined with mascarpone's tangy tartness and marzipan's rich creamy goodness. Mr. and Mrs. Cake baked it, and they've chosen Pinkie Pie -- who has more of their trust than she once did, since Pinkie's been demonstrating increased responsibility by babysitting the Cake Twins and working the counter at Sugarcube Corner -- to transport MMMM on the Friendship Express to the National Dessert Competition in Canterlot.
It takes the entire Mane Six Plus Big Mac to get the wobbly cake onto the train (including another Twilight Sparkle-created force field), and they're all going with Pinkie Pie to Canterlot. Except Big Mac, who never gets to go anywhere fun. The six of them aren't alone on the train, as they're joined by extremely French griffon Gustave, who is also traveling to the National Dessert Competition and quite convinced his dramatically back-lit éclairs will win.
Enter the gruff-talking Donut Joe, last seen as the proprietor of Canterlot's 24-hour donut shop in "The Best Night Ever." His entry: Donutopia! (It's my favorite, probably because it looks the least sweet.)
The third and final guest chef is Mulia Mild and her chocolate mousse moose. Really, how does that joke not get done more often?
There is trash-talking among the chefs.
As the Cakes' proxy, Pinkie joins in, too. There's a lot of distrust on the Friendship Express this evening.
So much so that after the chefs go to bed, Pinkie is convinced they're going to sabotage MMMM.
Her friends elect not to help her stand guard, so Pinkie does it all by herself, though unlike Twilight Sparkle, she's not quite as adept at tizzying herself into staying up all night.
She's awoken by a shadowy figure, and after a chase through and outside the train, Pinkie returns to the unmolested MMMM. The next morning, however, she discovers that molestation did in fact occur.
This is where the episode gets largely unrecap-able for me, since it's a full-fledged mystery investigation, an Agatha Christie homage with heavy emphasis on visual clues. They do use the more familiar Arthur Conan Doyle iconography of the pipe and deerstalker hat. (Speaking of, wanna know the best Sherlock Holmes movie ever? 1989's Without a Clue, which you can watch in its entirety on YouTube.) But before you do that, let's watch Pinkie's three very wrong theories of how the other chefs got to MMMM. In the first, Gustave is a villain from a Mack Sennett silent film ...... Donut Joe is a suave secret agent ...
...and Mulia is a ninja. Yeah.
After there's been further dessert carnage and the mystery is finally solved, Pinkie reports in her Shoehorn that you shouldn't jump to conclusions until you find out all the facts. Then, jump away!