Who Is Thetis?
Sea goddess and mother of Achilles
Thetis is a goddess of the sea and the mother of Achilles. She is one of the Nereids, the daughters of the old sea god Nereus, and she married the mortal king Peleus.
In Episode 1, she hears her son weeping on the shore and rises from the gray sea like a mist to listen to him. She then goes up to Olympus, clasps the knees of Zeus, touches his chin, and pleads with him to restore her son's honor.
In Book 1 of the Iliad, Achilles recalls that when the other gods once tried to bind Zeus in chains, Thetis summoned a hundred-armed giant to rescue him.