The Hogwarts Express' true nature as revealed by keys
i want the trolley witch and the train to be the same entity
some eldritch being bound to the train tracks, watching over the boundaries. a threshold spirit, offering food and drink to its guests. a being that lives and dies in only a day, retreating back to its lair beneath the station until the time comes to print the tickets again. lists presented, tickets formed. a covenant older than trains, and in the engine room you can almost hear the beats of wings, pounding hooves on the edge of your senses.
on the six-thousand-four-hundred-and-seventy-third day of the pact (the wizards would call this september of nineteen-ninety-three) there is a stop on the line. this has happened before; for five-thousand-four-hundred-and-ninety-five days it made many stops, collecting guests one or two at a time. what is unusual is this: the guests it has stopped for have no tickets. the guests it has stopped for refuse all food. the guests it has stopped for are cold, and it, for the first time in a long time, for the first time since it folded flesh and bone and wooden twigs away under a gleaming red shell, it feels rage. guests, uninvited! guests, refusing offerings! guests, cold in a way it cannot, will not allow near its banked-fires-in-ashes. it fights the creeping darkness as the not-guests ooze through it, burns lamps so bright and hot that when it stops they still glow with heat, rips carpets up from tacks to strangle the cold. it is not enough. and while it prepares its last, most desperate defense, it feels another it rise from somewhere within. but the not-it it feels does not have wings, or hooves, or a gleaming shell. the not-it is made of gas-light and memory, and the not-it too refuses food and has no ticket. but it does not eat its food either, and what need has it for a ticket when it makes the tickets? no, it will not fight this not-it. it will watch with many eyes in many places, as it watches all things. maybe on the next day of the pact it will make its own not-it. the exchange-of-rounds-and-food has a sliver of wood-and-tooth. the guests will see that it is a good host. it is always a good host, for as long as the journey lasts. (the wizards will later wonder how dementors managed to cause this much damage to their train) (the carpets are ruined! all the lamps broke! and the train won't even let them fix it!)
so if it's not clear, the "uninvited guests" are the dementors, who dont have tickets, the "not-it" is lupin's patronus, which is also a guardian spirit, and the "exchange-of-rounds-and-food" is the trolley witch, who is more of an extension of the express than a person and has a "wand" made of bits of the express' previous physical forms. (the "wood-and-tooth"
yeah i was like 'would an eldritch spirit understand what money is?' probably not, if it's considering everyone on the train "guests" and you don't make your guests pay for food, so the train is very confused about why people keep giving it round things but it'll take them anyway. maybe humans give their hosts gifts when their hosts give them food? that sounds right? well, the guest-gift-rounds are pleasantly cool and shiny, so it puts them in its lair "under the station" "under the station" in this case means "a gigantic cavern full of coins and old/lost belongings with a wholeass train circled up in the middle like a strangely-segmented dragon"
there are guests who say it is just a train. it is not. no. it is a train, but it is more than a train. it is the platform and the tracks and the station; it is the journey, it is a host. it is a being made entirely of liminal spaces--transitions without anything to transition to. it is a being of fire and movement: steam curling from the breath of a massive horse, misty curls from atop a broom, waves bellowing out of a smokestack. it takes its guests from their first steps onto the station to the very doors of their destination, for until the journey is over it is still their host, no matter if they are aboard or away from it. a good host feeds their guests, keeps them from harm in their halls, offers many things and accepts very little. a good host provides and protects. It is a good host. It may even be the best host; what other can claim six-thousand journeys? it is old, though its form is new, and the pact it abides by has changed with the days. the laws of hospitality it holds higher have not