A strange phenomenon has overtaken Ponyville and its number of residents is effectively doubled because of it. Every pony wakes up to find a complete stranger in their room, and the mane-six in particular are introduced to a bunch of peculiar ponies.

Applejack decides to head out and ask Ponyville's resident scientist and librarian for an explanation on what's going on. It doesn't take long for Twilight to figure out who and what the extra ponies are.

Things seem to be working out for a while, however, after a few days it becomes evident that Ponyville is not compatible with the large amount of newcomers. Mayhem ensues, and (naturally) it's up to the mane-six to find a solution to the problem.

Cover art provided by MrAlienBrony and SpiritofthwWolf.