With Robert Plant making an appearance on "The Only One," this first -- and only -- traditional "solo" record from the god-like master of riffology was snapped up and feverishly cranked by every Zeppelin-withdrawaling teen and 20-something in the U.S. when it came out in 1988. "Liquid Mercury" comes close, but Outrider doesn't have any riffs as mind-blowing as, say, "Moby Dick," "The Ocean," "Livin' Lovin' Maid," "Misty Mountain Hop," "Black Dog," "The Rover," "Kashmir," "Over the Hills and Far Away," "In the Evening" -- hell, what do you want? How many riffs can one man write?