'The Tholian Web' by Judy Burns and Chet Richards

Answering a distress call from the U.S.S. Defiant, the Enterprise arrives in an uncharted area of space; but although the Defiant is visible on the viewscreen, sensors indicate that it is not there. When Captain Kirk, Lieutenant Commander Spock, Doctor McCoy and Ensign Chekov beam across to the vessel they discover that the entire crew is dead, apparently killed in a bizarre mutiny. McCoy is unable to determine why the crew died, but after his hand passes through a body he realises that the U.S.S. Defiant is dissolving. They attempt to return to the Enterprise, but the spatial instability means that only three can be transported at a time; Kirk stays behind while the others beam back, but when Chief Engineer Scott then attempts to bring him aboard, the captain vanishes. Spock calculates that they have a little over two hours to retrieve him. However, the Enterprise crew soon begins to fall victim to the same violent madness that the Defiant crew experienced. A Tholian spaceship then arrives and informs Spock that the Enterprise has violated their space; the Vulcan is able to persuade the Tholian commander to allow them to wait until Kirk can be retrieved, but the Tholians' prescience has increased the spatial instability, and the captain fails to reappear. After Spock reluctantly declares his captain dead, a funeral service is held. But the Tholians have now decided that Spock has lied to them, and they open fire on the ship. The Enterprise retaliates, and the Tholian vessel is disabled; however, another vessel soon joins it, and together they begin weaving an energy web that will destroy the Enterprise upon completion...

William Shatner (Captain James Tiberius Kirk), Leonard Nimoy (First Officer Lieutenant Commander Spock), DeForest Kelley (Doctor Leonard H. ‘Bones’ McCoy), James Doohan (Chief Engineer Montgomery ‘Scotty’ Scott), Nichelle Nichols (Lieutenant Nyota Uhura), George Takei (Lieutenant Hikaru Sulu), Walter Koenig (Ensign Pavel Andreivich Chekov), Majel Barrett (Nurse Christine Chapel), Sean Morgan (Lieutenant O'Neil), Barbara Babcock (Tholian Voice), Barbara Babcock (Voice of Comander Loskene)

Directed by Herb Wallerstein

TX:
15th November, 1968

Notes:
*Featuring Captain James Tiberius Kirk, First Officer Lieutenant Commander Spock, Doctor Leonard H. ‘Bones’ McCoy, Chief Engineer Montgomery Scott, Lieutenant Nyota Uhura, Lieutenant Hikaru Sulu, Ensign Pavel Andreivich Chekov and Nurse Christine Chapel