Thespis from An Actor's Life for me is yearning for his muse and refuses to perform without his muse in the audience. Head for the House of Aphrodite.

The House of Aphrodite is not far from the Temple of Hephaistos and Weapons Storage in Athens. Look for a woman in a dark red robe; this is Aikaterine.

As it turns out, the guards are threatening her if she goes near Thespis. She asks for Commander Rhexenor to be eliminated...and to have his sword returned to her (haha). Gather information from her and go guard hunting.

Commander Rhexenor is a member of the Cult of Kosmos. Run to the Weapons Storage in Athens; meditate until night time. Call Ikaros to mark the target and other enemies. Sneak inside the area and stick to the bushes, take out guards if needed. Head northwest; the commander should be asleep inside a small blue tent. Kill him and confirm the kill.

Return to Aikaterine at the House of Aphrodite. There is an option to romance her here. No matter what happens, she will return to Thespis.

Return to Aristophanes. He's no longer at Perikles's Residence. Instead, he's at the Theater of Dionysos next to the Akropolis Sanctuary. After a short conversation with him, a cutscene of the comedy will play and poor Kleon will stomp out. After this scene, the mission will end.