During the ninth day of the Mahabharatha war between the Pandavas and the Kauravas, the third yuga had ended and last yuga - Kali yuga had started. However because of the power of Lord Krishna, Kali could not spread all through the earth. After departure of Shri Krishna, Kali started spreading evil in the minds of people. But Kali could not enter Parikshit's kingdom as he was a kind ruler.
One day, the Kali had requested Parikshit that Kali Yuga started and he should be permitted to enter his kingdom. Kali said, the four ages – Satya yuga, Dwapara yuga, Treta yuga and Kali yuga are a cycle. Parikshit permitted him to enter his kingdom with a condition that he does not hurt innocent people and will not be everywhere. He can only be where there is gambling, drinking of alcohol, prostitution or immoral relationship between man & woman and violence. Kali asked Parikshit one more place as all these four places are dirty. Then Parkshit permitted him in gold.
One day, Parikshit was searching his belongings. Out of curiosity, he checked one box left by his grandfather. It was containing a gold crown. Without thinking consequences, he wore the crown. This crown was of Jarasadh. Son of Jarasadh had asked Sehdev to return the crown of his father. But Sehdev was not interested as Bheem brought it forcefully. Hence the crown was unjustifiably acquired. Money or gold acquired unjustifiably brings Kali. As Parikshit wore the crown, kali entered in mind of Parikshit.
After a few days, Parikshit wearing the crown went for hunting in a forest for the first time. He killed many animals. He found that he had separated from his army. In the afternoon, he felt hungry and thirsty. He saw an ashram of sage and entered into it. Shamik rishi was in Samadhi (deep meditation). Parikshit thought he is king of the kingdom and rishi is not welcoming him. He thought, sage is acting for not to welcome him.
A dead snake was lying near the sage. Out of anger, Parkshit picked the dead snake and hanged around the neck of the sage. When Shamik’s son, Shringi come to ashram, he got furious to find a dead snake on his father's neck. He removed the snake. With a deep breath he closed his eyes and meditated. He realized that it was King Parikshit who had done this. Shringi cursed Parikshit in anger that he will die within seven days by biting of a Takshak nag as he had put snake in his father’s neck.
When King Parikshit had heard the curse, he immediately gave up the throne up to his son Janamejaya. He proceeded to bank of Ganges River and abandoned food and water. Parkshit thought that Shringi rishi has blessed him as he was indulged in sensual pleasures. Otherwise, he would not have taken vairagya (detachment).
Many saints came to meet him but nobody could assure him Moksha in seven days. Under the divine inspiration, Shukdev ji had come to provide moksha to Parikshit. Shukdev ji says Parkshit, he should not worry and assured him to offer whatever he got. Seven days are sufficiently left. Be in present and worship almighty. Parikshit listened to the Bhagawat Purana the whole of the next seven days from Shukdev ji. As Parikshit listened to the stories, his fear of death went away. He realized the ultimate truth of life and death and gave up his body to attain moksha.
After seven days, Takshak nag came and bit Parikshit’s body after the soul left it.
Shrimad Bhagwat Mahapuran by Shri Ramchandra Keshav Dongra ji Maharaj