Led Zeppelin Begin Mysterious Countdown on Facebook
Signs point to announcement Thursday, but tour is unlikely
 Led Zeppelin are in the midst of a mysterious countdown on Facebook. The band on Saturday posted the word “Five” in the stylized typeface of their fourth album, garnering nearly 37,000 “likes.” Yesterday, they followed with “Three.” Last night they posted this video:
If they keep going, the countdown will end Thursday, revealing . . .  well, who knows? Optimistic fans online are talking about a possible tour, though singer Robert Plant has made it clear he’s not interested. The more likely scenario, The Guardian reports, is the announcement of a new DVD chronicling the surviving members’ last reunion, at London’s O2 Arena on December 10th, 2007. Guitarist Jimmy Page’s manager, Peter Mensch, would seem to be lending support to the DVD theory: “It’s almost here,” he tweeted Saturday. “I’ve seen it and heard it. Almost five years to the day.” Â