A "devil's dye" was the name given in the 16th century to the blue obtained from the woad plant. It was said to corrode fabrics and bring bad luck, according to popular superstition, as also recorded by Johann Krünitz in his Oeconomische Encyclopädie of 1773. But it is precisely this plant that farmer Christoph Rieger wants to cultivate and he wants to become rich with it, the colour is in demand. Too late he realises that obstacles are being put in the way of his plans... Christoph's story was inspired by a true incident that took place in Horka on 25 April 1510. The appendix contains a selection of the medicinal herbs in use at the time and mentioned in the novel, as well as a glossary.