The latest episode of Star Trek: Discovery, "Light and Shadows," has subtly explained an emotional decision made by Spock in Star Trek: The Original Series. As Discovery inches ever closer to the classic Star Trek era, it's establishing subtle links to the Kirk era. This latest episode, for example, included a Klingon Mind Extractor, a weapon seen in classic Trek.
"Light and Shadows" saw Burnham leave the Discovery in pursuit of her brother, Spock. While she was gone, the Discovery's attempts to learn more about the Red Angel led to them unintentionally opening a time rift, and Captain Pike and Ash Tyler piloted a shuttle close to the rift in order to launch a probe. As an experienced Starfleet test pilot, Pike rightly believed himself to be the most qualified, but the whole mission turned out to be a big mistake when the shuttle ended up trapped inside the rift.
Pike knew that the Discovery would be looking for them, and so came up with an innovative approach to help them find the shuttle - one that will be very familiar indeed to fans of Star Trek: The Original Series. The Captain began releasing plasma from the nacelles in five-minute bursts, essentially leaving a plasma trail for the Discovery to detect. It was revealed this is an old trick that Starfleet pilots were taught at flight school, and was just the kind of thing a former test pilot would have thought of. It worked, after a fashion; the temporal eddies meant the trail was fluctuating dramatically, but Lieutenant Stamets was able to deduce where and when he could beam aboard the shuttle to pilot it to safety.
It's not the first time Star Trek has shown Starfleet using a variation on this idea. One episode of Star Trek: The Original Series, "The Galileo Seven," saw Spock and a Starfleet away team crash a shuttle on a desolate, primitive world. Although McCoy was able to conduct sufficient repairs to allow takeoff, the shuttle didn't have enough fuel to break the planet's gravity, and there was no way to contact the Enterprise to tell Kirk where the away team was. Spock came up with what was portrayed as a desperate strategy, dumping the shuttle's remaining fuel and igniting it as a flare. In the aftermath, Kirk attempted to get Spock to admit that this idea was born of desperation - an emotion - rather than logic; Spock refused to concede the point, but did confess to stubbornness.
Star Trek: Discovery suggests that Spock wasn't being emotional after all. Instead, he was using a tried-and-tested method that pilots were taught at flight school, and that he could conceivably have learned when he served under Captain Pike. Spock had been part of the Enterprise's initial five-year exploratory mission, after all, in which there'd no doubt have been a number of occasions when away teams were sent off in shuttles. It would hardly be a surprise if Pike taught this trick to all of the Enterprise away teams, as an emergency method of establishing contact in the event something had gone wrong. Unlike Pike, James T. Kirk was always on the command track, and he'd never have heard of the idea of using a fuel dump as a signal.
Star Trek: Discovery streams Thursdays on CBS All-Access and the next day internationally on Netflix.