Oscar just charged into my office, ran up the cat tower to the top of my bookshelf -- in which he has shown no previous interest -- and ran across the bookshelf to the corner. He then knocked an umbrella off the second shelf, ran back down to the floor, sniffed at the umbrella once, and left. He is now stretched out at the top of the stairs.
Billy and Whitey didn't seem to hear the instructions from Great Basement Cat, but clearly Oscar did. Or something.