When Katherine Choong invites her friend Eline Le Menestrel to climb ‘Zahir’, a classic multi-pitch route in the Swiss Alps and one of the country’s most challenging, Eline agrees, but on one condition: they must travel using only eco-friendly means. As the days pass on the wall, they realize just how ambitious their project is. The long distance between bolts, the tiny holds, and the exhaustion from cycling push them to their limits. Fueled by determination and enthusiasm, will Eline and Katherine find their own Zahir?