Sometime in the mid- to late-2000s, I remember reading a book that was about an organization of extradimensional beings who control the minutiae of the universe. I remember very little about it, but this is what I do recall:

• It's a YA novel
• Main character is a human recruited by said extradimensional beings
• They control basically every aspect of physics, like making sure to fill up the rainclouds with the appropriate amount of water and lightning
• Seconds (as in the unit of time) exist as a physical object, there are also firsts and thirds
• There may have been some pun between splitting the atom and the phrase "split second"?
• The world these beings inhabit is the place where all mysteriously lost objects end up, I think? There's a "barrier" between the worlds that's only visible from their side.
• The general tone of the novel is absurdism, but I'm pretty sure it has its serious points.

Does anyone have any idea what book or series this might be?

Sometime in the mid- to late-2000s, I remember reading a book that was about an organization of extradimensional beings who control the minutiae of the universe. I remember very little about it, but this is what I do recall:

• It's a young adult novel
• Main character is a human recruited by said extradimensional beings
• They control basically every aspect of physics, like making sure to fill up the rainclouds with the appropriate amount of water and lightning
• Seconds (as in the unit of time) exist as a physical object, there are also firsts and thirds
• There may have been some pun between splitting the atom and the phrase "split second"?
• The world these beings inhabit is the place where all mysteriously lost objects end up, I think. There's a "barrier" between the worlds that's only visible from their side.
• The general tone of the novel is absurdism, but I'm pretty sure it has its serious points.

Does anyone have any idea what book or series this might be?