“Then Achilles killed Thersites because he was mocked by him when he reproached him, claiming he loved Penthesileia. A conflict arose among the Achaeans over the murder of Thersites. After that Achilles went sailing to Lesbos where, after he made a sacrifice to Apollo, Artemis and Leto, he was cleansed of the murder by Odysseus.”
“Many divergent things are said about the death of Theseus. Many say that he was bound in the underworld until Herakles restored him; but of the things I have heard, these are the most believable: Theseus attacked Thesprotia in order to kidnap the wife of the Thesprotian king and lost the majority of his army in the process. In fact, both he and Peirithous—who went on the expedition also looking for a marriage—were captured and the Thesprotian king kept them imprisoned in Kikhuros. There are many other things in the Thesprotian land worthy of seeing—the shrine of Zeus at Dodona and an oak sacred to the god. Near Kikhuros is a lake called Akherousia and a river called Akheron. A really unpleasant river called the Kokutos flows there too. Homer must have seen these places and was emboldened to use their names for places in Hades, transferring the names for the rivers from the Thesprotian landscape.
While Theseus was imprisoned, the children of Tyndareus attached Aphidna, sacked it, and installed Menestheus as king. Menestheus had no thought for the children of Theseus who had retreated to Elephenor in Euboia; but because he knew that Theseus, if he ever were restored from the Thesprotians, would be a difficult opponent, he attempted to improve the affairs of the common people, so that when Theseus was released, he was expelled from the land. As a result, Theseus went to Deukalion in Crete—when he was carried by winds to the island of Skyros, the Skyrians treated him well because of the fame of his family and the worth of the deeds which he accomplished himself. For these reasons, Lycomedes planned his death.”
The details of Theseus’ death are reported elsewhere:
Plutarch, Life of Theseus 35.4
“When he came to [Lycomedes] he was seeking that his lands be returned to him so he might live there. Some report that Theseus was asking him for help against the Athenians. Lycomedes, either because he feared the man’s reputation or as a favor to Menestheus, led Theseus to the highest part of the land on the pretense of showing him the territory. Then he pushed him from the rocks and killed him. Others say that Theseus fell on his own, going on a walk after dinner.”