Secret of the Monks

..in a remote abbey on the edge of a small town, mysterious incidents have been occurring for weeks. In the study of a priest, 4 monks were most recently found dead - all with black fingertips and black tongue tips. To rule out any devilish work, some suspicious brothers of the abbey were brutally tortured and interrogated and a single woman from the surrounding village was found guilty of witchcraft and burned. However, since all measures and investigations into this case have so far remained without result, one of the brothers secretly led you into the old building to find out who or what is behind the events. As all the monks disappear into the chapel for communal prayer, you enter the mysterious rooms in the highest tower of the abbey... Is the murderer hiding there?