From the days unknown, the devas or devatas (gods), living in heaven and the danavas or asuras (demons), often fought for the supremacy of the three worlds, Swarg, the heaven above, Marta, the land of living of the humans and the animals and Patal, the underworld. Although the devas always managed to overpower the asuras in the battles to retain their supremacy, the asuras bounced back each time by reviving their dead back into life, by the grace of their guru, the preceptor, teacher and priest, Shukracharya, who got the boon of Mritasanjeevani Vidya, the knowledge of imparting life to the dead, from Lord Shiva. However, it reflected an adverse effect on the devatas, because whenever there was a war, the killed asuras were brought back to life, whereas the devas were losing their men continuously, as their guru, Brihaspati was in dark about the Mritasanjeevani Vidya.
The situation rang the bell of warning for the devas, since it became evident that soon the danavas would outnumber them and oust them from heaven.
In view of the critical situation, the devas conceived a plan and requested Kach, the young and handsome son of Brihaspati, to visit Shukracharya and request him to accept him as his disciple, with the intention to learn the Mritasanjeevani Vidya. Considering the position of the devas, Kach agreed to the proposal, went to meet Sukracharya and after introducing himself as the son of devaguru Brihaspati, requested Sukracharya to kindly accept him as his sishya or disciple. Although they belong to the opposite camp, Shukracharya accepted Kach as his disciple, since according to the prevailing social convention, no Brahmin guru could turn away a Brahmin disciple.
Accordingly, Kach started studying in the house of Shukracharya and helped in various daily domestic activities of his gurugriha, as per the traditional system and gradually, the good-natured, prudent and intelligent Kach became one of the favourite disciples of Shukracharya.
By that time, Devyani, the beautiful daughter of Shukracharya, became intensely attracted by the melodious music and beautiful paintings of Kach, which turned into love over time. She did not try to hide her feelings from the man she loves and in return, Kach’s behaviour also revealed his attachment to Devyani, as he regularly used to pick the most beautiful flower of the thorny cutch forest for Devyani. Devyani was impatiently counting the days and was anxiously waiting, when Kach would complete his education and would pray for her hand to make the end to her celibacy. At her request and insistence, Shukracharya finally agreed to teach Kach the Mritasanjeevani Vidya, the knowledge of imparting life to the dead, but not immediately, he will have to wait for the proper time.
However, since the day Kach arrived at Shukracharya to become his disciple, he earned the displeasure of the danavas, as he belongs to their enemy camp and they rightly guessed that Kach has been implanted by the gods or the debatas to break their monopoly over the Mritasanjeevani Vidya. Finally, when they found that Kach has become a favourite of their guru, they became more alarmed, apprehending that Shukracharya would ultimately teach him the secret of Mritasanjeevani Vidya.
As the intimacy between Kach and Devyani added fuel to their suspicion, they decided to kill Kach, before he takes leave from his gurugriha and before he gets any chance to deprive danavas of the opportunity of annihilating the fighting force of the debatas. Nevertheless, they decided to wait for an ideal opportunity to do away with him.
Finally, one day, when Kach was herding the cattle of Shukracharya near the forest, the danavas decided to utilize the opportunity, as he was alone, killed him, cut the body into pieces and fed the wolves. But as the sun went down and the cattle returned home without Kach, Devayani became anxious about the safety of her beloved, informed her father about her concern and requested him to revive Kach, if he was killed. Concerned by the grief of his only daughter, Shukracharya brought Kach back to life by applying the Mritasanjeevani Vidya, who returned from the forest hale and hearty. However, the failure did not deter the danavas to give up their plan and they got their next chance soon, when one spring afternoon, Devyani requested Kach to bring a special kind of flower for dressing her hair, a special type of flower which can be found only deep in the forest. The waiting danavas gladly took the advantage of the situation and as Kach, eager to please his ladylove, entered deep into the forest to collect those wildflowers, they killed him again and threw his bones and flesh into the sea. Nevertheless, this time again, Shukracharya brought him back to life at the earnest request of his daughter.
After failing twice, the danavas thought a lot about the disposal of the body of Kach and after killing him for the third time, they burnt the body to ashes, mixed the ashes with Somras, a ritual drink in ancient India, prepared with the juice from a plant, known as Somelata and offered the drink to Shukracharya, who drank it, without hesitation and without knowing anything about its preparation. Later, when Devyani informed her father about the absence of Kach, even in the late evening, Shukracharya came to know by his meditating power that Kach is in his stomach. Although he became mad about the danavas as they cheated on him with a dirty trick, he cannot do anything about it immediately as the situation placed him in a helpless position. Now, if he revives Kach by Mritasanjeevani, Kach would come out by tearing his body, causing his death. The findings made Devyani distressed, as she cannot think of living without Kach and at the same time cannot think of reviving Kach in lieu of the life of her father. However, after pondering for a while, Shukracharya taught Mritasanjeevani, the knowledge of reviving the dead, to Kach, who was inside his stomach and then revived Kach, who came out tearing away Shukracharya’s body. Although Shukracharya died in the process, Kach revived his guru by applying his newly earned knowledge of mortification to save the situation for all the persons concerned.
Finally, as he completed the mission of learning the Mritasanjeevani Vidya, Kach asked for the permission of Shukracharya to leave gurugriha for his heavenly abode to which Shukracharya agreed. But his decision broke Devyani’s heart, as she expected Kach to pray for her hands, marry her and live their lives together. She tried to stop him, implored him with tearful eyes requested him not to leave her, reminding him of their time together, but could not change his decision. In his turn, Kach tried to explain that he was sent by the devatas with a mission and is committed to return after completing his mission, so it would be unethical for him to become romantically involved with a woman and stay back forever. He also tried to establish that a marital relationship between them would be unethical, as she is the daughter of his guru and is like a sister to him. Apart from that, while Shukracharya is her father, he was also reborn from his body, making him as good as his brother. Devyani felt humiliated and insulted, refused to accept Kach’s argument, as they were born to two different persons and asked Kach, despite being aware of his situation, why he cheated her for such a long time, playing the role of her lover, giving her the false impression that he would marry her at the end. His rejection made Devyani furious and she cursed him that he would forget the Mritasanjeevani Vidya he learned from her father and would not be able to use the knowledge of mortification when needed. Strangely, instead of trying to pacify the woman he loved, Kach in his turn also cursed her that none of the sons of sages would ever marry her. After the incident, they parted ways, never met again and thus ended the tragic love story of Kach and Devyani.
The story of Kach and Devyani is one of the numerous episodes included in the great Indian epic, Mahabharata and also mentioned in the Matsya Purana and the Agni Purana.