Master Po (Keye Luke) is Donald Cory, the governor of this little Penal Colony, Steve Inhat and Batgirl (Yvonne Craig) are inmates. Yvonne is a green skinned "Orion Slave Girl" "Marta" with a knack for writing other people's poetry and dancing.
Queen to Queen's Level Three anyone?
This episode brings in Lord "Garth" of Izar (Inhat) and the framework of a story about a great Starfleet battle at "Axenar" - A story that was to be finally told in a Fan Film production. We at least got a great "Prelude to Axenar" that sets up how and why the Constitution Class ships were built. Garth was part of that, when he was a respected Starship Captain.
But the process that healed him has also driven him mad, and has also given him the ability to shape shift.
And when Kirk and Spock deliver a needed medication to the colony, they are cleverly tricked by Garth. What ensues is a tale to make sane minds go mad, because when there is a Shape Shifter around, you just don't know who's who.
Queen to Queen's level 3.
We get to see the proper use of the Neural Neutralizer here, which Bookends "Dagger of the Mind", and maybe that is referenced by the fact that "Marta" (Craig) has one (A Dagger).
Dagger of the Mind was about how a Doctor was assaulting people with the Neutralizer, under the guise of an "all is well" appearance. Here, the kooks have taken over Arkham Asylum, an even more secured institution that Tantalus 5. Where in "Dagger of the Mind", Spock could not get in, in this, Spock cannot get out. Both institutions had a planetary shield, which work both ways.
This episode was partially written by science fiction author Jerry Sohl, who wrote "The Transcendent Man" and some other novels.
Queen to King's Level 1!