The USS Enterprise enters an uncharted region of space answering a distress call from her sister ship, the USS Defiant.
As they approach the Defiant's last known location, the Enterprise's engines begin to lose power and sensors detect a nearby dimensional fracture in space that seems to be the cause of the energy drain.
The Defiant appears on the monitor, adrift with a strange green glow surrounding the hull. Strangely, sensors show no indication that the vessel is there.
There are no lifeforms detected, and Lt. Uhura reports that no communications can be established with the ship.
Captain Kirk assembles a boarding party consisting of himself, Dr. McCoy, Mr. Spock and Mr. Chekov to beam over and investigate. As the boarding party prepares to beam over, they all suit up in environmental suits.
Once their helmets are secured they are ready for transport.