Ragnarok is a series of events that will bring about the death of major figures of the Norse pantheon. The gods, Odin, Thor, Freyr, Heimdallr and Loki will all die in a great Battle. One of the first indicators of Ragnarok is the death of Balder, most beloved of the gods and the son of Odin and Frigg. The gods are not the only beings who will suffer during Ragnarok. It is foretold that mankind will be locked in battle for three years, that families will turn on and abandon each other. There will be various natural disasters which will result in the world being submerged in water.
Afterwards the world will resurface fertile and new, the surviving Gods will meet and two humans will repopulate the world. The most important factor to remember about Ragnarok is that it is cyclical, it starts with destruction and begins with a new world – it does not signify an end but rather a beginning.
Crossley-Holland, K. 2011. The Penguin book of Norse Myth: Gods of the Vikings. Penguin Books.