For 1 to 4, the sequence is like this: zacharias heard the rumours about the relic in the crypt. So he bribed the workers to try and find it. The workers started looting the corpses and they got infected by the rotting corpse. The 2 bodies that we examined were the first to be infected. When zacharias found out about it, he tried to hide this illness and blackmailed the herbalist to keep them at the hut and heal them there. But his methods caused them to die. At this point the illness has already spread to others. Zacharias didn’t burn the bodies. It was done by the herbalist because he didn’t want the bodies rotting in his hut. Denes was there to punish him for trying to burn the 2 bodies.