Synopsis

Dave offered up a mock opening sequence for the second presidential debate, strikingly reminiscent of *Magnum, P.I.*. Debra Messing promoted her series, "The Starter Wife," with a pointed remark directed at Sarah Palin. Alan's tour of the *Late Show* control room met with playful disruption. John Carter, founder of Alianca da Terra, spoke about the challenges facing the Amazon rainforest. And Tegan and Sara performed their song, "Call It Off."