Hardware Space
It’s sort of like Terry Pratchett’s L-Space, except that it involves giant hardware stores, has considerably fewer books, but also considerably less active danger. You see, all hardware stores across the multiverse — at least, all hardware stores above a certain cultural level — are interconnected, spatially. Maybe temporally, too? It’s hard to say. Nobody’s ever reported a time-slip. But then, nobody’s ever reported a time-slip, so it’d be evidence either way, right?