Professor Wilkers saw the trip to Thailand as a welcome change. But already in Bangkok, the starting point of his research into the origin of the drugs whose abuse he is trying to combat as a member of an international commission, he encounters extreme contradictions. The Swiss doctor is tempted to solve them, as the claims of the rich silk manufacturer Tracy Blake sound truthful and bitter, yet extremely strange. Leo Wilkers decides to embark on a life-threatening venture: He moves into the mountains near the border with Burma. Up there, in the village of Muong Nan, whose headman is at the same time in prison in Bangkok worrying about who in the capital might be interested in his arrest, Wilkers learns about the necessity of poppy cultivation in these areas.