The Enterprise is flying through the Hekaras Corridor searching for a missing medical transport when she's disabled by a verteron mine disguised as a signal buoy. She's then boarded by two Hekaran scientists who claim that warp drive damages subspace in that region of space, risking the formation of a subspace rift. The crew is skeptical until one of the scientists creates a warp core breach on her ship, destroying it (with her on it) and creating the rift.
The Enterprise must find a way to rescue the imperiled transport without making a bad situation even worse.
- Cassandra Truth: Serova feels this way with nobody believing her.
- The Extremist Was Right: Discussed; while Serova's theories are proven to be entirely correct, Data points out that her behavior in the course of trying to prove said theories was, if anything, counter-productive.
- Fantastic Racism: Worf shows this towards the Romulans — again. Declaring when discussing the new Warp-5 restrictions that the Klingon Empire will (of course!) accept the Warp-5 limit restriction but that the Romulans never will, as if its an obvious truth.
- Foreshadowing: Geordi references a new ship named Intrepid which, given the timeframe, is presumed to be the first of the Intrepid-class and thus the sister of Voyager.
- Green Aesop: The "pollution" from warp engines is a thinly-veiled reference to other forms of pollution in the real world, especially the types caused by automobiles and other vehicles of various types. As a result of this episode, the Federation imposes a speed limit of warp 5 on all starships except for cases of extreme emergency, until a more permanent technological solution can be found.
- Insufferable Genius: Serova. Her scientific skills may be spot-on, but her people skills are terrible.
- Jerkass Has a Point: Serova is pushy and uncompromising, and gets pissy anytime someone questions her theory. She turns out to be right.
- Layman's Terms: Geordi rattles off a string of Technobabble on how they can escape the rift, which he simplifies by comparing it to surfing.
- The Main Characters Do Everything: Data and Geordi, the science officer and chief engineer, spend the first two acts doing maintenance that should be a junior officer's job. Justified in this instance, as Geordi is in a competition with a rival engineer on another ship to reach ever-higher efficiency ratings to one-up each other, so he's performing maintenance that isn't really necessary and thus wouldn't be assigned to his engineers who would be assigned to routine maintenance elsewhere.
- Nice Job Breaking It, Hero!: Serova's extreme method of proving her theory creates the Negative Space Wedgie that she and her brother had been trying to prevent, both endangering two Federation starships and messing up the climate on her home planet decades before anyone's ready to deal with it.
- No Warping Zone: The Hekaras Corridor becomes this thanks to the proven threat of another Negative Space Wedgie.
- Sibling Yin-Yang: Serova is passionate, stubborn, and antagonistic while Rabal is calm, reasonable, and diplomatic.
- Spreading Disaster Map Graphic: Near the end, the consequences of heavy ship traffic through the corridor is projected on a map like this. Within mere decades, the entire sector would be a minefield of the type of subspace warp rifts that Serova caused.
- Start X to Stop X: Serova tries to prevent a coming disaster by revealing it in a way that can't be ignored. However, in doing so, she actually causes the disaster to happen. (Although it should be noted that she did intentionally create the rift some distance away from the planet, thus giving them time to mitigate the effects.note Had she simply allowed regular warp traffic down the Corridor to continue eroding subspace, for all anyone knows a rift might have formed right next to the planet, rendering it uninhabitable before they had a chance to do anything about it.)
- Status Quo Is God and What Happened to the Mouse?: The idea that warp engines could be dangerous to the fabric of universe is not mentioned again in The Next Generation or other Star Trek series. The warp 5 speed limit is referred to a couple of times in the following episodes, but after that it disappears too with no explanation. Most fans just Handwave it away with the assumption that someone simply invented a safe warp drive and everyone converted to it.
- Word of God has stated that Voyager's unique warp engine design is that safe version; by the time the Sovereign-class ships were launched, warp nacelles were further refined to avoid the affect without the need for changing configuration like Voyager's.
- What makes it even worse is that, as worded in the episode itself, the Warp 5 speed limit applies only to the corridor itself, not the galaxy at largesubsequent misunderstanding of this in future episodes is what led to the sense the status quo was being enforced, when there wasn't even really violated.
- The warp five limit is frequently referred to in extended universe novels that take place between this episode and First Contact... and just as frequently noted that the Federation is the only spacefaring society that actually holds to it. The episode wound up being a far more accurate metaphor for real life ecological protectionism than it intended, as it's only a single "country" (the Federation) being scolded for something everyone is doing, and it's only that same country that does anything about it, while the rest feel free to pollute to their heart's content.