Cam goes up. He takes pictures and lets his computer assemble them into a topographical map and proposes to a different program that he could put a dam here or there or wherever and plugs in Steel's figures for the water volume. He finds where it's going to drain, overflies the area edge to edge to edge and finds nothing more than wildflowers, and then goes to catch up with Steel - for higher confidence in his software results he needs to know how much it rains around here and upstream, but he's almost ready.