The Enterprise is sent to investigate the disruption of the Gamma VII-A solar system and the destruction of the U.S.S. Intrepid, staffed by Vulcans. When they arrive, they find a large dark mass floating in space. This ep has a great introduction w/ Spock realizing that his own people died and sensing their “astonishment” (fine acting from Nimoy). Spock doesn’t know how the ship is being drained of energy and pulled towards this “hole in space.” Life support systems are diminishing quickly. Stimulus is injected in the Bridge crew (esp. Kirk) to keep them going despite exhaustion from a previous mission.

Drawn into the mass, they find a huge amoeba-like creature. Kirk and McCoy wonder that mankind’s sole destiny may be in repelling such invaders of our galaxy; our species may act like antibodies of the galaxy-body, fending off invading cosmic viruses. Were this creature to reproduce, as the crew discovers it is about to, it would eventually fill the entire galaxy. The crew is working as a team under pressure against an unknown threat. There is the drama of Spock and McCoy competing to see who gets to take the shuttlecraft to get a closer look and research further. Kirk must decide which of his two friends to send on the dangerous mission. Scotty is worried about the engines, which are losing power fast. There is a lot of atmosphere, foreboding, character development, and dialogue (incl. science and medical talk).

Mr. Spock: I’ve noticed that about your people, Doctor. You find it easier to understand the death of one than the death of a million. You speak about the objective hardness of the Vulcan heart, yet how little room there seems to be in yours.

Dr. McCoy: Suffer the death of thy neighbor, eh, Spock? Now, you wouldn’t wish that on us, would you?

Mr. Spock: It might have rendered your history a bit less bloody.