Arriving at the "amusement park" planet for
some relaxation, the Enterprise finds that the
planet's keeper is now dead and the untended machinery is constructing dangerous images
from the crew members' thoughts.
An accomplished singer, Nichelle Nichols as Lieutenant Uhura, sang in this episode as she had done in a
number of original STAR TREK episodes. In this episode, she vocalized for almost 40 seconds.
This episode's co-writer, Chuck Menville, also wrote another animated STAR TREK episode
"The Practical Joker". Chuck Menville, along with Len Janson, also wrote for several other Filmation series from 1969 to 1976.
There is a page in this site that examines the Hover Robots
that were seen in this episode.
The phaser bore is a powerful piece of Starfleet equipment used when a landing party's mission requires tunneling underground. The phaser bore is capable of digging through 20 meters of rock per minute.
When the commandeered ship's computer briefly cuts off the artificial gravity, the crew are sent floating about the ship. This is another example of scenes which would have cost too much to do in live action.
The animation sequences featuring the red dragon were apparently reused in the first episode of Filmation's Space Sentinels (1977-78) series, albeit with one less head. The episode entitled "Morpheus, The Sinister Sentinel" just so happened to be written by Len Janson and Chuck Menville the authors of this animated episode.
In this and other episodes, the sciences insignia erroneously appeared on red uniforms.
The correct spelling of this episode's co-writer is Janson. All episode guides of the animated
STAR TREK universally mispelled his name as Jenson.
This episode had a visual error: the hangar deck doors opened from one side, while in the animated episode
and the original series, the doors open from the center like a sideways clam shell.
Like in the original series episode "Catspaw", in this episode Kirk and his men are briefly menaced by a giant domestic cat who threateningly howls and swats at them.
Another visual error: McCoy's tricorder strap disappeared in a bridge scene.
This episode had another mistake in which Sulu was erroneously shown calmly sitting on the bridge
while he was actually imperiled on the planet's surface.