FRONTLINE/World investigates one of its own stories, "The Play Pump," which promised to use a merry-go-round and the power of children to help meet the dire need for fresh water in southern Africa. After FRONTLINE/World first aired the story in 2005, major donors in the United States -- and the U.S. government itself -- launched a multimillion-dollar campaign to install the device in thousands of African schools and villages. Now, correspondent Amy Costello investigates what happened to those communities, as the promise of the PlayPump fell short and the device's biggest American boosters began to back away from a technology they had once championed.

Host Elyse Luray pilots an airplane to relive the memory of one of America's first, and youngest, barnstormers. Pilot "Cromwell Dixon" lost his life at 19 when his airplane crashed. Then, details in "Bartlett's Sketchbook" suggest the scenes illustrate the first ever US-Mexican border survey. Host Eduardo Pagan wonders whether the sketchbook made that journey, and if it belonged to Bartlett? Finally, a dumpster find may be a jazz history treasure. In the encore segment, Tukufu Zuberi sets out to find whether these metal "Duke Ellington Plates" printed the first copy of the Ellington hit, Take the A Train.

A gripping documentary about Bobby McMullen, a competitive mountain biker on a mission to race the most demanding downhill course in the country, riddled with obstacles and flanked by steep, life-threatening cliffs. If you think that sounds challenging, here's something that will really amaze you: Bobby is blind. With the help of a guide and a rigorous training schedule, Bobby is determined to race his bike down this course. Through thrills, spills and jaw dropping helmet camera footage, we see how Bobby uses humor, determination, and unshakeable optimism to battle adversity - both on and off the bike.

Beloved for his talents as a singer, songwriter and guitarist, country superstar Brad Paisley returns to Austin City Limits to highlight songs from his new album 5th gear.