Arthur Penhaligon is not your typical hero-type. He is a bit of a weakling, actually, since his asthma makes it difficult for him to do much of anything athletic. One day, as Arthur is lying on the ground [trying not to die from an asthma attack] he starts to hallucinate. At least, that is what he thinks is happening when a couple of strange men appear out of nowhere. Mr. Monday is in a strange wicker wheelchair that looks more like a bath, and he is being pushed by a much older man named Sneezer. As the men approach, Arthur can hear them discussing whether or not they should give Arthur “the key” — a long and pointed metal object that resembles a minute hand on a clock — and some sort of book. Sneezer claims that the boy is the rightful heir, but that he is about to die and that Mr. Monday could reclaim the key as soon as Arthur has died. As strange as that discussion might have been, Arthur finds it even stranger that he really does have the “key” and book in his possession after the men have gone away again. And, to make matters worse, he is now seeing all sorts of strange things that other people don’t seem to notice — like dog-faced men (Fetchers) and a giant house that appeared overnight. When the Fetchers unleash a “sleepy plague” that threatens the existence of humanity, Arthur needs to use the book and the key to enter the house and save the world from Mister Monday. Is this truly his fate? Or has Arthur gotten in way over his head?