> 
> Under **the seams of the hour**, boys struggle in a dozen different
>  arenas. Four hundred children crawling along the edge of a razor.
> 
> 
> 

* From *[All the Light We Cannot See](http://www.anthonydoerr.com/books/all-the-light-we-cannot-see/)* by Anthony Doerr

What does *the seams of the hour* mean here?