Fluttershy goes to the Frozen North at the edge of Equestria once a year to observe the wildlife that inhabits it. She was on the train back home.

Blue Seas was on his way to his new job in Baltimare where he'd work aboard the Serendipity, a huge palace-like cruise liner. He rode the same train.

Neither predicted a terrifying derailment in the middle of the icy wilderness.

Cover art by yours truly.