When young Ehrich Weisz — the future illusionist, Harry Houdini — follows his brother, Dash, through a strange portal, he is thrust into an alternate New York where the immigrants aren't just different ethnicities but different species. He finds work in this strange steampunk world as a Demon Hunter, tracking down dangerous otherworldly visitors that threaten the city's safety, while hiding his own foreign origins. A curious medallion, his only clue to finding his brother, leads Ehrich to a mysterious woman caught up in interdimensional intrigue, and he must learn who to trust as he unravels the truth if he ever wants to find his way home.