Here's a fairytale from The Brothers Grimm

The blue light

There was once a soldier who had faithfully served his king for many years: when the war was over, however, and the soldier was unable to continue to serve because of all the wounds he had received, the king said to him ‘You may return home, I no longer need you: you will receive no more wages, since they are only paid those who serve me in return.’ At this, the soldier had no idea how he was to scrape a living: he left in sorrow and walked all day long until that evening he came to a forest. When it grew dark, he saw a light which he set out towards and arrived at a house where a witch lived. ‘Please give me some shelter for the night and a little to eat and drink,’ he said to her, ‘for otherwise I will surely die.’ ‘Oho!’ she answered, ‘who would give a run-away soldier anything? I will, however, be merciful and take you in, if you do what I ask of you.’ ‘What do you ask of me?’ the soldier asked. ‘That you dig through my garden tomorrow.’ The soldier agreed to this and the following day he toiled away, but was unable to finish by the time evening came. ‘I can see,’ the witch said, ‘that you cannot work any longer today: I am willing to let you stay for one more night, but for this you must tomorrow chop up a cartload of wood until it is firewood.’ The soldier spent the whole day doing this, and that evening the witch suggested to him that he should stay one more night. ‘You need only do a small job for me tomorrow, behind my house there is an old dried-up well, my light has fallen down it, it has a blue flame and does not go out – you are simply to fetch it up.’ The following day, the old woman led him to the well and lowered him in a basket. He found the blue light and made a sign that she was to haul him up again. She started to haul him up, but just before he reached the edge, she stretched out her hand and wanted to take the blue light from him. ‘No,’ he said, noticing her evil intent, ‘I won’t hand over the light until I am standing safely with both feet on the ground.’ Then the witch flew into a rage, let him fall back down into the well and went away.

The poor soldier fell – without injuring himself – onto the moist floor, and the blue light kept on burning, but what good was that to him? he realised that he could not escape death. He sat there for a while, downhearted, then by chance he dipped into his pocket and found his pipe there which was still half-stuffed with tobacco. ‘That is to be my one last pleasure,’ he thought, took it out, lit it with the blue light and started to smoke. When the smoke had drifted around the cavern for a while, there was suddenly a small black manikin standing in front of him, who asked ‘Master, what is your wish?’ ‘Who am I to wish things of you?’ the soldier replied in astonishment. ‘I have to do everything,’ the manikin said, ‘that you ask me to.’ ‘Very well,’ the soldier said, ‘you can start by helping me out of this well.’ The manikin took him by the hand and led him through an underground passage, but he did not forget to take the blue light along with him. On their way, the light revealed to him the treasures that the witch had collected and hidden there, and the soldier took as much gold as he could carry. When he was back at ground level once more, he said to the manikin ‘Now go and tie up the old witch and take her to the court.’ Not long after, she came hurtling by as fast as the wind on a wild tom-cat with a wild shriek, and only a moment later the manikin was back again, ‘everything carried out as ordered,’ he said, ‘and the witch is already hanging from the gallows. – Master, what else is your wish?’ the manikin asked. ‘Nothing more at present,’ the soldier replied,’ you can go home: just be here at once if I call for you.’ ‘All you need do,’ the manikin said, ‘is to light your pipe with the blue light – and I will be standing before you.’ After which he disappeared from sight.

The soldier returned to the town he had come from. He entered the finest inn and had beautiful clothes made for himself, then he ordered the innkeeper to arrange as magnificent a room for him as possible. When it was ready and the soldier had moved in, he summoned the black manikin and said ‘I have served the king faithfully, but he sent me away and would let me starve, now I will have my revenge.’ ‘What am I to do?’ the manikin asked. ‘Late at night, when the king’s daughter is lying in bed, you are to bring her here asleep, she is to serve me as my maid.’ The manikin said ‘for me that is an easy matter, but for you a dangerous one. If it is found out, things could go badly for you.’ When the clock had struck midnight, the door flew open, and the manikin entered carrying the king’s daughter. ‘Aha, there you are, are you?’ the soldier cried. ‘Get down to work at once! Go fetch a broom and sweep the room.’ When she had finished, he ordered her to come to where he was sitting, stretched his feet out towards her and said ‘pull off my boots’, then threw them in her face, and she had to pick them up, clean them and polish them. But she did everything he commanded her to, without resisting, silently and with half-shut eyes. At the first cockcrow, the manikin returned her to the royal castle and to her bed.

The next morning, when the king’s daughter had got up, she went to her father and told him she had had such a strange dream, ‘I was carried through the streets at lightning speed and taken into the room of a soldier, who made me serve him as his maid and wait on him and do all the chores, sweep the room and polish his boots. It was only a dream, yet I am just as exhausted as if I had done all of this.’ ‘The dream might possibly be true,’ the king said, ‘I will give you a piece of advice, fill your pocket with peas and make a small hole in your pocket; if you are fetched once more, they will fall out and leave a trail in the street.’ When the king said all this, the manikin was standing invisible beside him and heard everything he said. That night, when he carried the sleeping king’s daughter through the streets once again, some peas did indeed fall out of her pocket, but they were unable to leave any trail, for the cunning manikin had strewn peas out in all the streets in advance. And the king’s daughter was obliged once more to perform the duties of a maid until cockcrow.

The next day, the king sent his people out to look for the trail, but it was in vain, for in the streets the poor children were sitting harvesting peas – they said ‘last night it rained peas.’ ‘We must think of something else,’ the king said, keep your shoes on when you go to bed, and before you leave from there, hide one of them. I’ll be able to find it.’ The black manikin heard the suggestion, and when the soldier that evening asked him to fetch the king’s daughter once more, he advised against it and said, there was no means of defeating such an act of cunning, and if the shoe was discovered in his room, things could go badly for him. ‘Do what I tell you,’ the soldier replied, and the king’s daughter had to work as a maid a third night; but before she was carried back, she hid one shoe under the bed.

The next day, the king had the shoe searched for throughout the town: it was found in the soldier’s room and the soldier himself, who at the manikin’s request had made off for the gate, was soon caught up with and thrown into prison. He had forgotten to take his best possessions with him when fleeing – the blue light and the gold, and all he had left in his pocket was a ducat. When he now, loaded down with chains, stood at the window of his prison cell, he saw one of his comrades passing. He tapped on the window-pane, and when the man came up, he said ‘be so kind as to fetch the small bundle that I have left behind me at the inn – here is a ducat for your trouble.’ His comrade ran off, and brought back what he desired. As soon as the soldier was alone once more, he lit his pipe and had the black manikin appear. ‘Have no fear,’ he said to his master, ‘go to where they would take you, and allow everything to happen, just take the blue light with you.’ The next day, the soldier was put on trial and, although he had done nothing evil, the judge condemned him to death. As he was being led out, he asked the king for a final favour. ‘What favour is that?’ the king asked. ‘That on my way out I am allowed to smoke one last pipe.’ ‘You may smoke three,’ the king answered, ‘but do not imagine that I will spare you your life.’ Then the soldier took out his pipe and lit it with the blue light, and when a couple of rings of smoke had risen from it, there stood the manikin with a small cudgel in his fist and said ‘What is my master’s wish?’ ‘Strike the false judges and their henchmen to the ground for me, and do not spare the king either, who has treated me so badly.’ Then the manikin set about them like lightning, zick-zack, back and forth, and whoever was even touched by his cudgel dropped to the ground and did not dare to move any more. The king was terrified, and started to plead, if only for his life, gave the soldier the kingdom – and the princess as his wife.