The Paris Review tweeted about Minetta Brook, the subterranean stream that flows beneath Greenwich Village. It used to flow freely across the landscape, and was commonly used as a fishing stream by locals. Now it is viewable only through hidden grates in basements and sub-basements.  Most people are not aware of its existence.  

I am thinking that every vital literary neighborhood has its own subterranean Minetta Brook which percolates up and periodically infuses the landscape ... Likewise every literary work of strength, depth, and originality has its own Minetta.

One analyzes a literary work, seeking to plumb the subterranean stream of its creative genius - its minetta.