D12 Reasons Why The Bookstore Nearby Which I Meant To Go To But Never Did Has A Heavy-Duty Lock And A Cardboard Sign That Says "DO NOT UNLOCK!!!" On Its Door

1. The bookstore's moved out and the property hasn't been leased to another tenant yet.

2. A pipe burst and the place needs major clean-up and repairs.

3. It's actually always had that, and I've only just now looked closely enough to notice. Perhaps the store is only ever used as a covert meeting-place.

4. By accident or conspiracy the bookstore wound up with the diary of the daughter of a major local political figure, which reveals some deeply compromising blackmail on that figure. The bookstore's owner has shut down the place out of paranoia, and sequestered themself to corroborate the claims of the diary and use its contents to make a lot of illicit money.

5. There was a break-in and a very rare, very valuable tome was stolen - the owner hasn't gotten the police involved because they also stole the tome in the first place, and so are conducting their own private investigation - discrete, morally-flexible help wanted.

6. A recent shipment of books was contaminated with a species of hallucinatory mildew that has caused the owner to perceive themself as being in a fantasy realm where all their favourite literary characters have come alive. They've locked the place up so they don't have to share their "paradise".

7. They were parasitized by a species of beetle that camouflages itself as books, and lays its eggs in librarians and bookstore owners who don't get enough visitors, and so won't be quickly missed. Fearing that their coleopteran tormentor would soon after spread to the whole world, the bookstore owner quarantined themself inside their shop - though they really needn't have bothered.

8. The owner discovered an eldritch grimoire, an artifact from another dimension near-totally opposed to our own. Where the grimoire is from, the relations of information and matter are inverted - information is not recorded in or produced by matter, but rather matter arises from the content and processing of information. The owner believes that with the book they can take over the world, and so studies it and its interactions with our universe obsessively.

9. The owner made a deal with the Devil that granted them tremendous talent in writing and critique, so long as they gave a thousand people a book that on reading would change their life for the worse. After getting cold feet while selling the 998th book, and worrying what the Devil would do to them after finishing their end of the bargain, the owner sealed up their store and now prays fervently in a double-ring of holy water and motel side-table bibles for salvation.

10. The owner has been occupied transcribing their own biorhythms into logorhythms - encoding every biological process they've got from heartbeat to circadian flow to cellular mitosis into books of poetry - a lengthy, grueling, exacting process. If they complete the process correctly, then they'll live so long as people flip through the pages of their books, the necessities of their life outsourced from body to art.

11. Enough books in the store were pulped from trees from the same ancient forest that they reached a critical mass - the books' remembrance of being trees with old, old memories leaked into reality, creating a landscape vaster than the property should have been able to contain. Certain that they could make discoveries that would earn them far more money than their store ever did, the owner ventured into this psychic forest where arboreal recollections of rocks, animals, and rivers mingled bizarrely with the contents of the books they would become.

12. In the beginning, God created light. Soon after that (relatively speaking), Adam was tasked with naming all the world's creatures, and Eve with granting them faces. When Adam fell from grace he was in the middle of speaking a name, a name he could no longer complete. Left incomplete, that name had no ending. Without an ending, it had no meaning. Seeking both, that name sought others among the children of Adam to speak its fullness. It has been seeking for a very long time. A portion of that name ended up in a book in the bookstore, and the owner read that portion of the name, and so became possessed by it and has been compelled to speak it endlessly - and to speak it to others in order to spread it. In a final moment of self-control and lucidity they sealed themself within their bookstore, and warned others away.