THERE ARE TWIN GATES OF SLEEP: OF THESE ONE is said to be of horn, through which an easy exit is given to true shades, and the other is made gleaming with white ivory, but this way the Powers of the Underworld send false dreams to the air above. With these words, he escorted his son and the Sibyl together, and despatched him through the gate of ivory. Aeneas made his way to his ships, and rejoined his friends.