At a certain moment the search looks like having gotten to a dead end - a vital hint had been written on the door of an outbuilding, but the door is not there any more. It turns out, however, that the door in question was used as an improvised stretcher on which a wounded rebel was carried to a neighbouring village during the Polish 1863 uprising against Russian rule - and that after this use, the door had been installed at the village church, where Adam duly finds it and writes down the clue.