★★★★ December 15, 1967 Season 2 Episode 13
If you want to see where we are…and you missed a few…HERE is a list of the episodes in my index located at the top of my blog.
This show was written by Gene Roddenberry and Art Wallace
As a young officer on the USS Farragut James T. Kirk encountered a strange creature and was lucky to live to tell the tale. Reminding him of that fact is a new crew member assigned to the Enterprise, the son of the late commander of the Farragut played by Stephen Brooks. It’s with some mixed emotions that William Shatner deals with Brooks.
The monster is an intelligent gas, made of an element that’s not supposed to exist naturally, and that’s able to transform itself as a means of camouflage.

Complicating things is the fact that the Enterprise is on a critical rescue mission already when Shatner commits his vessel to fight the creature. Something that for once Leonard Nimoy and DeForest Kelley are in agreement on (they agree he shouldn’t fight it) and question Shatner’s judgment. As the title suggests…he is obsessing over this creature instead of the critical mission the Enterprise is on.
This is a good episode although there was no prior hint that Kirk was the sort of man who would be recklessly obsessive yet here we are expected to believe that he would abandon an urgent mission without even contacting Star Fleet about the entity. All in all we learn more of Kirk’s character in this one.
Ralph Senensky’s direction keeps this classic Shatner episode tight, exciting, and well-shot.
From IMDB:
The ship which Kirk served on for his first deep space mission is disclosed to be the USS Farragut, and was named after David Glasgow Farragut, a flag officer of the United States Navy during the American Civil War. He was the first rear admiral, vice-admiral, and admiral in the United States Navy and is credited for uttering the phrase, “Damn the torpedoes, full speed ahead!”*, disregarding all danger while charging into enemy waters off the Alabama Coast. -This is an abridged version. He said “Damn the torpedoes. Four bells, Captain Drayton, go ahead. Jouett, full speed.”*
Second episode in a row in which Captain Kirk’s capacity of command is questioned.
This episode establishes the fact that Vulcan blood is copper-based, unlike human blood which is iron-based.
Only time in the series where phasers are said to have a disruptor setting.
“Obsession” is a “startrekified” version of Herman Melville’s Moby Dick, a seminal American novel first published in 1851. Captain Kirk of the Enterprise is Captain Ahab of the Pequod and the Gaseous Creature is the White Whale.
The only episode to have a security guard as the central story.
The unseen ship, the USS Yorktown, recalls the name of the ship in Gene Roddenberry’s original story concept he pitched to the networks in 1964, the SS Yorktown commanded by Robert April. The concept evolved to the USS Enterprise commanded by Christopher Pike in Star Trek: The Cage (1966), then James T. Kirk.
Filming took place during the Jewish holiday of Yom Kippur. Director Ralph Senensky was an observant Jew and left the set at sundown. Producer John Meredyth Lucas took his place. Lucas went on to officially direct three episodes of this series.
In an effect unique in the series, the phaser beam that Garrovick fires at the creature is outlined with a dark border.
Dikironium, of which the cloud creature is made, is an element with symbol Dk, has an atomic number of 112, and an atomic weight of 300. It was first discovered on the planet Vulcan. Element 112 was not discovered/produce until 1996 and was named Copernicium. Its atomic weight (technically, atomic mass) is 285.
This takes place in 2268.
In the medical records library between Spock and McCoy, there is a large object which looks like a vertical DVD rack. The same large object was in Harry Mudd’s laboratory in Star Trek: I, Mudd (1967).
Vocalization in the opening theme song is less prominent behind the instrumental than previously since vocalization began in Season 2.
Hikaru Sulu does not appear in this episode.
Director Ralph Senensky has said, having worked with actor Stephen Brooks on many previous occasions and liked him, that he specifically asked for Stephen Brooks for this show.
Summary
Captain Kirk is haunted by a creature from his past when conducting a mining survey on a planet. He first encountered it as a lieutenant aboard the U.S.S. Farragut and blames himself for freezing in a moment of crisis, causing the death of many crewmen. The creature is a cloud-like, gaseous being that lives on the red blood cells found in humans. Obsessed by his desire for revenge and to erase the memory of 11 years ago, he pursues the creature relentlessly, putting in jeopardy an assignment to collect essential medical supplies.
CAST
William Shatner…Capt. Kirk
Leonard Nimoy…Mr. Spock
DeForest Kelley…Dr. McCoy
Stephen Brooks…Ensign Garrovick
James Doohan…Scott
Nichelle Nichols…Uhura
Jerry Ayres…Rizzo
Majel Barrett…Nurse Chapel
Walter Koenig…Chekov
William Blackburn…Hadley
John Blower…Swenson
Frank da Vinci…Vinci
Steve Hershon…operations officer
Jeannie Malone…Yeoman
Eddie Paskey…Leslie
Basil Poledouris…Bardoli
