The Enterprise is temporarily in orbit around an alien "Starship" (actually an artificial planetoid approximately 217.352 kilometers in diameter) of unknown origin, aboard which Captain Kirk and a landing party of four are stranded. They are currently detained in a prison cell, awaiting interrogation.

Far more immediate is the condition of the Enterprise. The ship has been "snared" by wires apparently composed of the same alien craft (a substance harder than any known to Federation science) - wires which are draining off our power reserves at an alarming rate. We appear to have the choice of remaining on board the Enterprise (and crashing to the surface of the planetoid once our power is gone), or joining the Captain inside the alien spacecraft. A fascinating dilemma.