He first of all brought them under the hand of Clotho, and drew them within the revolution of the spindle impelled by her hand; from her they were carried to Atropos, who made the threads irreversible; whence, without turning round, they passed beneath the throne of Necessity; and when they had all passed, they moved on in scorching heat to the plain of Forgetfulness and rested at evening by the river Unmindful, whose water could not be retained in any vessel; of this they had all to drink a certain quantity--some of them drank more than was required, and he who drank forgot all things.

Er himself was prevented from drinking.
When they had gone to rest, about the middle of the night there were thunderstorms and earthquakes, and suddenly they were all driven divers ways, shooting like stars to their birth.

Concerning his return to the body, he only knew that awaking suddenly in the morning he found himself lying on the pyre.
Thus, Glaucon, the tale has been saved, and will be our salvation, if we believe that the soul is immortal, and hold fast to the heavenly way of Justice and Knowledge.

So shall we pass undefiled over the river of Forgetfulness, and be dear to ourselves and to the Gods, and have a crown of reward and happiness both in this world and also in the millennial pilgrimage of the other.
The Tenth Book of the Republic of Plato falls into two divisions: first, resuming an old thread which has been interrupted, Socrates assails the poets, who, now that the nature of the soul has been analyzed, are seen to be very far gone from the truth; and secondly, having shown the reality of the happiness of the just, he demands that appearance shall be restored to him, and then proceeds to prove the immortality of the soul.

The argument, as in the Phaedo and Gorgias, is supplemented by the vision of a future life.
Why Plato, who was himself a poet, and whose dialogues are poems and dramas, should have been hostile to the poets as a class, and especially to the dramatic poets; why he should not have seen that truth may be embodied in verse as well as in prose, and that there are some indefinable lights and shadows of human life which can only be expressed in poetry--some elements of imagination which always entwine with reason; why he should have supposed epic verse to be inseparably associated with the impurities of the old Hellenic mythology; why he should try Homer and Hesiod by the unfair and prosaic test of utility,--are questions which have always been debated amongst students of Plato.