Admins:  With all due respect to Roger Linfield - RIP, I believe his descriptions and other comments have missed the actual second pitch and so probably some of the third as well.  My description below includes those.

This route is billed as the easiest route that goes up the full height of Intersection Rock and as reasonable way to downclimb from the top. The below description is based on Vogel's  "Joshua Tree West" Falcon 2006 guide including the P3 exit details as drawn in the photo on page 451.

P1:  Move up and left across a slab, go up a chute, and move right into a pod on a ledge just below a vertical chimney / crack.  Belay here. Or for better P2 lead protection, just pro for the follower and traverse right into the dark tunnel. Don't exit the tunnel.  Belay. Headlamp may help.

P2: Move the belay if P1 ended at the pod.  Climb straight up into the chimney and stand on easy ledge that is outward from formation's center. Find good pro in the darkness.  Traverse the ledge back in the direction of the P1 pod.  At ledge's end, make one or three chimney moves up to good hands. Follow vertical crack (ish) up until breaking out onto a non-typical ledge-like area with obvious crack heading up and right at the back of the "ledge".

P3: Make some moves to climb the crack up and right until on easy terrain. Continue right (30 feet?) until can finish up a short, easy, vertical chimney / crack. Near the middle of the traverse, to keep things low 5th class, move away from the cliff face onto boulder-y terrain to then finish the rightward traverse to the chimney.

I have not tried to downclimb the above.  Also, we made a few moves straight up from the P1 pod but it felt quite a bit harder than old school 5.3.