Interrogation is on the Berlin Wall, and starts just left and uphill from Blitzkrieg. Climb straight up steep and blocky rock; pull the roof (11c/d), step right and climb up to a good rest on the left (12a). Head up and right onto a steep layback corner/ramp.Layback for several feet; then make a series of very difficult moves up and hard right (12c) until the climbing eases off. Climb up easy rock clipping one last bolt before the anchors.
Wow, this is actually a really good route -- sustained, complex, and varied climbing good rock. A long approach, but a [somewhat] of a hidden gem -- tough crux clip aside....
Hint: You can rap into the anchors for this route from above and hang draws on it. This also shortens the approach a lot. Park at the Dream Canyon parking lot and head left and down the hill, avoiding the private property. There is a faint trail that you will find between the edge of the woods and the clearing, follow that thru a wooded gully formed by a spring (wet) and then follow the trail up a short hill. Keep following the trail past an old fire ring on your right, then look for a cairn on your right slightly down the hill from the fire ring (which was at the high point). From the cairn, head down the hill to the top of the Berlin Wall. You will find a modern two bolt rap anchor in the rock on your left. Beware the loose rock in this spot and the exposure, its a long ways down if you screw up. From the rap anchors, rap to the top of either Interrogation or East Germany. Either route is easily equipped by rapping from the anchors on the routes. In other words, once you rap down to the route anchors, clip in, pull your rope and rap again. 60m works for sure, don't know about a 50m.
Its much easily to approach and climb this way than going up the yucky gully from Boulder Creek to the base of the Berlin Wall.