Climb up dirty blocks passing a couple bolts to a ledge below the obvious black corner. The dihedral is fun stemming the whole way up.
Like most on River Wall, with more traffic, this climb would clean up nicely.
Black Book is the black left-facing corner just to the right of the first two bolted routes you come to on River Wall (Pale Face 5.11 and Shake-n-Bake 5.12-).
You'll pass two bolts on your way up to the upper dihedral, where you'll want nuts and cams to 3". A 2-bolt anchor equipped for rappelling is at the top.