In 1865 Switzerland, a country mostly covered by high mountains, the main hobby is mountain-climbing. For some locals it's a personal passion and for others it's a lucrative business. Many tourists, mostly rich foreigners and explorers, come to Switzerland to attempt world records by climbing mountain peaks that have never been climbed or seldom been climbed before. Of course, some of these brave explorers lose their lives in their dangerous quests. The local Swiss villages provide experienced mountain guides and porters to the mountain climbers willing to pay the price, in coins or lives. Kurtal is such a small Swiss village located at the base of the famous Citadel mountain. The Citadel is the highest and the most dangerous peak in the region. Many have died trying to climb it but for the past 16 years no one has ventured on it. The last man to lose his life on the Citadel was the famous local mountain guide Josef Matt who died sacrificing himself in order to save the lives of his clients for whom he was serving as a guide. Josef's son, Rudi, is raised by his mother and by his uncle, Franz Lerner, who is also a professional mountain guide. Rudi is only 18 years old but he dreams of becoming a guide like his father. His family disapproves of Rudi's dangerous aspirations and relegate him to much safer jobs, such as being the dishwasher at the local motel run by Herr Hempel and his daughter Lizbeth. Often times, Rudi sneaks out of the kitchen to go climb smaller mountain peaks for exercise. Rudi knows the local rumor claiming that his father Josef had discovered a secret path to the summit of the Citadel on the day he died. Rudi hopes to one day climb the Citadel himself and find the secret path to the top his father supposedly discovered. One day, Rudi is at work washing dishes at the motel and he decides to sneak out of the kitchen in order to do a bit of mountain climbing. On the mountain, Rudi finds a stranded foreign tourist who got trapped when he fell onto a crag into a crevasse. Rudi throws a rope into the crevasse and saves the man who is none other than famed British mountain climber Capt. John Winter. The Captain thanks Rudi for saving his life and explains that accidents on the mountain could even happen to the most experienced climber. On their way back to town, Rudi and the Englishman pass by Rudi father's grave and the two pay their respects. The Captain reveals to Rudi that he believes in the dream of finding Josef's secret path to the top of the Citadel. In town, the Englishman hires Rudi's uncle Franz Lerner as a guide and convinces him to allow Rudi to come along as a porter. He also buys a new complete set of equipment and climbing gear for Rudy. Secretly, the foreigner wants to take a closer look at the famed and evil Citadel. When Rudi's uncle finds out the real aim of Capt. John Winter, he vehemently refuses to be the Englishman's guide to the Citadel. The Englishman leaves town and Rudi's uncle sells Rudi's new climbing gear that was gifted to Rudi by the foreigner. However, Rudi's girlfriend Lizbeth has purchased the hiking boots from Rudi's uncle and gives them back to Rudi. For the next few weeks Rudi undergoes a strict training in mountain climbing and guiding under the supervision of Teo Zurbriggen, Rudi father's old partner. Teo tells Rudi to never work for praise, glory and rewards but rather for the safety of his clients. Soon after, the locals spot two men, climbing the Citadel, through a telescope. One of them is Englishman John Winter and the other is Emil Saxo, a Swiss mountain guide from a nearby rival village. The next day, curious onlookers spot three men climbing the Citadel. With Rudi Matt gone from the village and nowhere to be found, the biggest question in everyone's mind is - who is the third man on the mountain ?