The youngest engineer in the history of the Vanderbull Railroad Company is eager to prove herself with a new invention. But to do so, she may sacrifice going home for Hearth's Warming. A young girl must choose: her career or her family.
"The Iron Horse" gets a one-shot Christmas-- I mean Hearth's Warming special! Robot pony Turing Test needs a gift for Twilight and Spike, but wants to do something special. To do so, she'll go to the ends of Equestria!