In the days when Charles II was King in England, and Charles, Earl of Derby, was King in Mann, Peel Castle was always garrisoned by soldiers. The guard room was just inside the great entrance of the castle and a passage used to lead from it, through one of the old churches, to the Captain of the Guard's Room. At the end of the day one of the soldiers would lock the castle gates and carry the key through the dark passage to the Captain. The soldiers used to take turns to do this.
About this time a big black dog with rough curly hair was seen, sometimes in one room, next time in a different room. He did not belong to anyone there and apparently no one knew anything about him. But every night, when the candles were lighted in the guard room and the fire was burning bright, he would come down the dark passage and lay himself down by the hearth. He made no sound, but lay there until the break of day, when he would then get up and disappear into the passage.
The soldiers were at first terrified of him but after some time they were used to the sight of him and lost some of their fear, though they still looked upon him as something more than mortal. Whilst he was in the room the men were quiet and sober, and no bad words were spoken. When the hour came to carry the key to the Captain, two of them would always go together - no man would face the dark passage alone.
One night, however, one foolish fellow had drunk more than was good for him and he began to brag and boast that he was not afraid of the dog. It was not his turn to take the keys, but to show how brave he was, he said that he would take them alone. He dared the dog to follow him.
'Let him come,' he shouted, laughing; 'I'll see whether he be dog or devil!' His friends were terrified and tried to hold him back, but he snatched up the keys and went out into the passage. The Black Dog slowly got up from before the fire and followed him.
There was a deathly silence in the guard room; no sound was heard but the dashing of the waves on the steep rocks of the Castle Islet.
After a few minutes, there came from the dark passage the most unearthly screams and howls, but not a soldier dared to move to see what was going on. They looked at each other in horror.
Presently they heard steps and the rash fellow came back into the room. His face was ghastly pale and twisted with fear. He spoke not a word, then or afterwards. In three days he was dead and nobody ever knew what had happened to him that fearful night. The Black Dog has never been seen again.