BACHELOR PAD - "Bachelor Pad: The Final Challenge" -- Our remaining four couples - Vienna & Kasey, Michelle & Graham, Ella & Kirk and Holly & Michael - are summoned to Las Vegas to compete in the most daring competition in "Bachelor Pad" history. They will have 24 hours to master a terrifying Cirque du Soleil routine that takes professionals six months to learn. Trista Sutter, Jason Mesnick and Ali Fedotowsky will judge the couples' acrobatic expertise, eliminating one pair. The winning couple will choose who will join them in the finale, on "Bachelor Pad: The Final Challenge," MONDAY, SEPTEMBER 12 (8:00-9:00 p.m., ET), on the ABC Television Network. (ABC/RHONDA CHURCHILL) HOLLY DURST, MICHAEL STAGLIANO