. प्रलय is of four kinds. The first is नित्यप्रलय . This is the destruction going on daily for all animate and inanimate objects born on earth. The second is ब्राह्मप्रलय or नैमित्तिकप्रलय . The third is प्राकृतप्रलय . This is the great deluge made by प्रकृति (nature) at the end of a thousand चतुर्युगस् (four युगस् ). The fourth is आत्यन्तिकप्रलय . This is the union of the soul with the Supreme Being due to ज्ञान . Of the above the ब्राह्मप्रलय , or नैमित्तिकप्रलय happens at the end of a कल्प or a day of ब्रह्मा or a thousand युगस् . The nature of this प्रलय is as follows: At the end of a thousand युगस् the world will look famished. Then there will be excessive drought for a hundred years together and everything in this world would be destroyed then. Then महाविष्णु , lord of everything in this universe, would present himself in the seven big rays of the Sun and drink to emptiness all the waters of all the three worlds, earth, ocean and पाताल . Then by the divine power of महाविष्णु the seven rays of the Sun which had grown fat by drinking this water would become seven separate Suns. These Suns would burn all the three worlds including पाताल . Then the earth would look like the back of a tortoise ( कूर्मपृष्ठ ) At that time रुद्र , equal in brilliance to कालाग्नि , would from beneath burn the पाताल sending breaths from आदिशेस . After पाताल कालाग्निरुद्र would burn the earth and then the heavens. Because of this all the worlds would look like globes of fire. Then the inhabitants of these worlds would go to महर्लोक unable to bear the heat and from there to जनलोक . Thus विष्णु in the form of रुद्र would destroy everything

Then from the face of विष्णु would originate clouds and lightning in different forms. Those clouds would rain incessantly for a hundred years and destroy the fire prevailing everywhere. When the rains become unbearable वायु would encroach upon the seats of the सप्तर्षिस् in the ocean and by the breath of विष्णु destroy all the clouds. At that time विष्णु , lord of all, would lie on the back of आदिशेष in that one big ocean drinking वायु (air). विष्णु will lie thus for a period of a कल्प in yogic slumber meditating on वासुदेव taking the name मधुसूदन and form of ब्रह्मा praised by the सिद्धमुनिस् inside the ocean. After that he would take the form of ब्रह्मा and start creation.

In प्राकृतप्रलय this whole universe would lie in extinction for a period of two परार्द्धस् . One परार्द्ध is 100000000000000000 years (one followed by seventeen zeroes) and so the period of a प्राकृतप्रलय is double the above number of years. The world would then come into the grip of a great drought; fire would break out and burn away everything in this world from महत्तत्त्व to विशेष . Then prompted by the desire of विष्णु , प्रतिसञ्चरण (back into nature) would occur. Then जल (water) would absorb the गुणस् of भूमि like गन्ध (smell) and when the qualities of the earth are thus absorbed the earth would merge with प्रलय . जल is रसात्मक . अग्नि will absorb the रस of जल and जल would be kindled. The गुण of अग्नि is form and is in the form of Sun. वायु would absorb it and अग्नि would be destroyed. वायु would then become powerful and shake the world. The quality of वायु is touch and the ether would absorb that गुण of वायु and वायु would be destroyed. The quality of ether is sound and it would be absorbed by the elements. If the elements are absorbed one by one the earth would merge into water ( जल ) and जल in अग्नि , and अग्नि in वायु and वायु in ether and ether in अहङ्कार (ego). अहङ्कार would merge in महत्तत्त्व . This महत्तत्त्व would be absorbed by प्रकृति . प्रकृति has got two forms:- व्यक्त and अव्यक्त (Manifest and Un-manifest). The व्यक्त would merge with अव्यक्त . पुरुष is single, pure and without decay. But he is also part of परमात्मा (the Supreme Being). So प्रकृति and पुरुष would both merge into the Supreme Being. There are no distinctions, fabrications in परमात्मा , the lord of all. It is only an existence. It is such a परमात्मा that should be known and which itself is knowledge. The परमात्मा is beyond the आत्मा (soul). It is in such an indescribable परमात्मा that all are dissolved during a प्राकृतप्रलय . (Chapter 368, Agni Purāṇa).