When the Duplo destroy Bricksburg with the help of a mysterious race who call themselves ponies, Emmet and friends must think of a way to get their revenge... without Lord Business or Princess Celestia finding out.
Warning - Spoilers
Also, the "real" sort of cross over doesn't begin until "Play Nicely..."
I read maybe a bit to fast but why are suddenly the ponies there to destroy the City?
4268592 Because i couldn't think of a logical way to introduce ponies.
4268592 Also, sorry this reply took a week. I have no computer at my other parent's house.
I read the first chapter, was slightly confused as to what was going on.
I've just read the second chapter, now understand and commend the author on successfully ( by my standards ) crossing over the Lego movie and MLP in a way makes sense, uses what is available well, and should have been obvious to me from the get-go.