Vertex just outside the inner ring at about the 1 o'clock position. It appears to come off a single track that continues, while the two branches leave off back to the left 90 degrees to each other.
by Whoandwhatitis moderator
This looks like a #toughie. Looks like there may be #multiple #ocv, albeit 2-3 lines each. That line that appears to have a 90° angle in Normal view may be the two lines that cross paths in the Slice view.