Watch 123Movies. In this film, two people and two worlds meet. Craig DeMartino, an adaptive climber from Boulder (Colorado) and Kai Lin, an industrial engineer from Brooklyn (New York) team up to design a game-changing prosthetic foot. This is easier said than done. Early prototypes don't hold up to the rigors of straight-in crack climbing, but this unlikely alliance is determined to test the power of problem-solving, so Craig and Lin keep at it.