The USS Enterprise is called to Planet Q by Dr. Thomas Leighton, a friend of Captain Kirk's, ostensibly to investigate a possible new synthetic food source.
Leighton's true motivation, however, is his suspicion that Anton Karidian, the leader of a Shakespearean acting troupe currently on the planet performing Macbeth, is in fact Kodos the Executioner, former governor of the Earth colony of Tarsus IV.
Kodos had ordered, by invoking martial law, that half the population be put to death due to the food shortage provoked by a fungal disease that had devastated the colony's crops.
Riley heads for the ship's theater, where the troupe is performing Hamlet, and goes backstage, phaser in hand, to exact revenge for the death of his family.
[2] All first-season core Star Trek regular background players appear in this episode: Eddie Paskey (Lt. Lesley), Frank da Vinci (Lt. Brent), William Blackburn (Lt. Hadley), Ron Veto (Harrison), and Jeanne Malone (Enterprise yeoman).
Club gave the episode an A− rating, noting strong performances from the actors including a "great Spock/McCoy dynamic" and "some very credible acting from Shatner.
"[4] Keith DeCandido, writing for Tor.com, commended the acting of Moss, Shatner, and Anderson, but felt the episode had aged poorly in regard to being able to identify Karidian as Kodos only via an unreliable voice comparison.
[5] Jamahl Epsicokhan of Jammer's Reviews rated the episode 2.5 stars out of 4 and similarly praised the performances of Moss and Anderson, but criticized the ending, calling it "inappropriate".
[6] Michelle Erica Green of Trek Today also praised Moss' and Anderson's performances, but criticized the episode's script.