Thrace is mentioned in Ovid's "Metamorphoses", in the episode of Philomela, Procne, and Tereus: Tereus, the King of Thrace, lusts after his sister-in-law, Philomela. He kidnaps her, holds her captive, rapes her, and cuts out her tongue. Philomela manages to get free, however. She and her sister, Procne, plot to get revenge, by killing her son Itys (by Tereus) and serving him to his father for dinner. At the end of the myth, all three turn into birds – Procne into a swallow, Philomela into a nightingale, and Tereus into a hoopoe.