The legend has it that every Friday at midnight a headless rider appears on the Deep road at Hradčany, sweeping there and back for an hour, after which he disappears in the gardens of the Strahov cloister. The rider is a Premonstrat monk who bears his head in his arms.
It is the ghost of a monk who was passionately addicted to playing cards. One night the monk was called upon to help a man who had fallen terribly sick on the Deep road. Instead of helping him right away he let him wait
while he completed his foolish card game. In the mean time the poor man died.
When the monk finished his shameful diversion he realized he must make haste and galloped on his horse heading to the Deep road as fast as he could. All of a sudden the horse tripped on the bumpy track throwing off the monk who fell and broke his neck. From that night on the monk has been roaming the Deep road on his horse thus reminding all the clergy of his fatal negligence in such a crucial moment.