The Iliad by Homer Book 24 Page 6

Hector to be stolen; and yet this may hardly be without Achilles coming to know it, for his mother keeps night and day beside him. Let some one of you, therefore, send Thetis to me, and I will impart my counsel to her, namely that Achilles is to accept a ransom from Priam, and give up the body.”

On this Iris fleet as the wind went forth to carry his message. Down she plunged into the dark sea midway between Samos and rocky Imbrus; the waters hissed as they closed over her, and she sank into the bottom as the lead at the end of an ox-horn, that is sped to carry death to fishes. She found Thetis sitting in a great cave with the other sea-goddesses gathered round her; there she sat in the midst of them weeping for her noble son who was to fall far from his own land, on the rich plains of Troy. Iris went up to her and said,