When Derpy and Crafty Crate deliver a package to a parallel dimension of sweet and innocent ponies, things go awry, and Ocean Mist, protégé of Kimono, learns a lesson as she overcomes her limitations to help them out
Miner Derpy Hooves is sent deep into the crust of the planet Hockses to kill bugs, defeat interloping rival corporations, drill for precious resources, and mine like her life depended on it (which it does)
Lightning Dust strands herself in space. With no way to move her rocket, she'll die unless Equestria's Best and Brightest find a way to bring her home despite sabotage, snobbery, limited resources, and bureacratic incompetence.
Ditzy Do's eyes aren't broken. There's nothing wrong with her. She's just watching something. Something in the corner of your eye. For Goddess's sake, don't look.