American TV Crossover: Running Wild Across the Heavens, Answering to No One

When the train that travels through all realms descended from the heavens,

a man arrived in the myriad worlds who would become a headache for both villains and protagonists.

(200,000 words written in advance. The Thing and DNA: A.I. is complete.)

(Other possible worlds: Tomb Raider, Ultimate Nullifier, Stranger Things, Doctor Who, Harry Potter, DC, Marvel)