The Guardian of Forever is formed

The Guardian of Forever, the time portal portrayed in the original series episode, is an irregular ring (or torus) shaped structure around 3 metres (9.8 ft) wide.[123] The Guardian's next on-screen appearance was in the Star Trek: The Animated Series episode "Yesteryear" (1973), in which the Guardian's voice was provided by James Doohan (who portrays Chief Engineer Montgomery Scott).[5