Page 440 — The Gang's All Here
Now, you might ask why this joke wasn't made in the first session, when Canterlot was first mentioned.
That's a good question.
Transcript:(party)
DM: Alright, let’s settle down, shall we? There’s a game to be played! Ahem… PREVIOUSLY, IN EQUESTRIA… I wasn’t there, but I’m told that last week’s adventure had to do with Cerberus, the gates of Tartarus, a massive timberwolf, stampeding wildlife, an ancient Greek ghost, and something called “Pinkie Sense.” But while Ponyville was experiencing chaos on a grand scale, two party members were off in other parts of Equestria. Rainbow Dash sold her services as a mercenary for a week. Sadly, due to a loophole in her contract, she was unable to claim any loot.
Applejack: Wait, is this a reference to what happened at D&D Camp?
Rainbow Dash: Urgh… Yeah… I don’t wanna talk about it.
DM: Rarity, meanwhile, was spending the week in the royal city of Canterlot.
Pinkie Pie: Canterlot!
Rainbow Dash: Canterlot!
Applejack: Canterlot!
Fluttershy: It’s only a model…
Pinkie Pie: Ssh!
DM: Oh, for Pete’s sake…
Rarity: <sigh> Good to be back, indeed…
Applejack: Trust me: Compared to last session, this is nothin’.