In brief: Compelling, absorbing, intriguing, convincing. I think the season ends on a high note.

"Shockwave" is bookended with some chilling images that burned themselves into my mind. Those images are enough to elevate an already standout story into the realm of memorable excellence. Trek hasn't absorbed me in this way in some time. And I'm pleased also to report that there's a depth and emotional arc to this story that's convincing.

But more than anything, I think what makes "Shockwave" truly work is its tone of unrelenting weightiness, which is masterfully pitched. I suppose the credit should go largely to Allan Kroeker and the actors, who bring conviction and importance to every scene, in a restrained, understated way -- not an easy task.

The episode opens with a startlingly potent image: the surface of a moon being incinerated by a wave of cascading explosions, destroying a mining colony and killing 3,600 people. It's a disaster on a large scale, and initial evidence indicates the Enterprise shuttlepod's plasma emissions accidentally ignited atmospheric gases during a landing approach. The evidence is conflicting; Reed explains in no uncertain terms that procedures to avoid this possibility were followed to a T, even while forensic-like analysis reveals byproducts that could only have been produced by the plasma igniting the atmosphere.

I especially liked that the episode didn't merely use this disaster as a plot launcher, but also as the basis for Archer's soul searching. A quietly effective scene where he silently scrolls through a seemingly endless list of colonist names -- with pictures attached -- says it all. Archer submerges himself into a pit of self-punishment; as captain, he feels directly responsible for all the deaths.

Meanwhile, news from Starfleet suggests that the Vulcans (particularly at the behest of Ambassador Soval) will use this incident to cancel the Enterprise's mission and try to bottle Starfleet back inside our solar system for the next 10 or 20 years. Overreaction? Certainly. Someone needs to argue in favor of the value of Enterprise's mission. But being in his guilty pit of self-punishment, Archer seems content to accept whatever is handed down from above without a fight. Trip is in disbelief: "That's guilt talking, not Jonathan Archer."

Even T'Pol recognizes the absurdity in the Vulcans recommending the mission be canceled. She also recognizes that Archer's guilt is getting the best of him, and in a good scene where she shows herself trying to be an effective first officer doing what's best for the mission, she visits Archer in his quarters and asks him bluntly, "Is this what humans call feeling sorry for themselves?"

These notes are played just about perfectly. We can understand Archer's guilty reactions just as we can understand that they must not be allowed to take complete control of him; emotions must not prevail in allowing a knee-jerk verdict go the distance.

It's about here where an intriguing sci-fi plot all but rescues Archer from his own predicament. While I'm in favor of seeing characters resolve their problems instead of having the plot do it for them, in this case the plot is so clever that I was more than happy to go with the flow. Archer turns off the light in his quarters and suddenly wakes up in his apartment on Earth in the past. I liked the visual of Archer looking out a window over the city skyline -- like a dream image, it's a visual that feels familiar and yet doesn't belong -- and I liked Archer's puzzled but muted responses to this strangeness ("If you're telling me the last 10 months were a dream, I'm not buying it," he says, not even sure if he's talking to anyone but himself).

The not-so-dead-after-all Crewman Daniels (Matt Winston; see "Cold Front") pulled Archer into this past because it seemed to Daniels like a good hiding place away from the front lines of the Temporal Cold War. Or something. Daniels tries to explain the collision of past and future in the terms of how certain events haven't happened yet, to which Archer responds, "That's a load of crap and you know it" -- a perfect line of dialog. Daniels then proceeds to explain that the accident that destroyed the mining colony was engineered by the Suliban as a frame-up in an attempt to undermine Enterprise's mission and change history.

If there's a complaint to be made about the plot machinations here, it's that the information supplied to Archer from Daniels is so correct and comprehensive as to make Daniels storyline-omniscient. But then that's the whole point about this war waged through timelines -- he who has the best information wins.

In this case, Archer comes back to the present with a wealth of information that makes it possible to collect evidence proving the Suliban frame-up. The Enterprise crew does this by tracking down and disabling a cloaked Suliban ship, boarding it, and stealing data that documents the frame-up. Clever. (Perhaps even too clever, too perfect.) The action here is the polar opposite of Andromeda action; stealth, skill, and planning take the place of brute force and mindless shoot-outs, to the point that I don't believe we see a single Suliban get hit with a phaser beam. Whaddayaknow.

This raid subsequently prompts recurring Suliban villain Silik (John Fleck), under orders from his mysterious superior from the future, to track the Enterprise down and target it for destruction unless Archer agrees to surrender himself, for reasons not yet made clear. Archer agrees to surrender and places T'Pol in command of the ship, in a scene that is played with such earnestly serious gravity that it borders on being Earnestly Serious Gravity, but without going too far.

What can't come across in a review is the effectiveness of the material's tone throughout. When Archer turns the ship over to T'Pol, for example, it comes across as a major concession of defeat even as the actors and director remain restrained with dead-on delivery. Less proves to be so much more.

The ending is a time-manipulation twist in which Archer finds himself suddenly pulled into the 31st century by Daniels, who finds to his own dismay that this causes the 31st century to be radically altered for the worse. Here we get compelling shots of a city long since laid to waste. The season ends with Archer and Daniels apparently trapped in an alternate future no one had predicted. I loved the final zoom-out shot with the wrecked city landscape and skyscraper shells -- a haunting image that conveys an apt sense of isolation.

Of course, the funny thing about the Temporal Cold War is that it has no knowable direction and therefore no actual substance. By definition, we are in the dark, because it's not about what has happened or is happening, but what maybe "should" happen in one possible future. And in situations like this, writers have a knack for letting themselves off the hook in ways that aren't satisfying to the audience. It's the one worry that comes built into a setup like this.

One might also reflect that by its very nature, the Temporal Cold War (or any sort of time-altering premise, for that matter) is fundamentally ridiculous, since the participants think they can control history merely by manipulating certain events in the timeline. Just once I'd be interested in seeing a sci-fi time plot that plays closer to my own belief in ultimate chaos: If there's one tiny detail or even molecule out of place, the timeline is thus significantly changed in ways that can no longer be predicted (Run Lola Run supplies one of my favorite cinematic examples of this school of thought).

I digress. In a way, "Shockwave" is like a melding of Star Trek and The X-Files. Most important to note is that it's like the early seasons of The X-Files that used to interest me (as opposed to the infuriating self-parody that its later seasons became) -- a show that was sold on the genuine evocation of mystery, intriguing images, and characters who reacted to the bizarre with muted disbelief.

"Shockwave" contains a lot of familiar sci-fi ideas that can't be described as "new." But what I'm enthused about is that the episode puts them together in such a way that the storyline itself feels new. It seems capable of going anywhere, and indeed it does go in directions we might not have anticipated at the beginning. Even for the Trekker who has seen everything, "Shockwave" manages to bring plenty to the table. Can the follow-up next season pull the characters out of this dilemma plausibly? I'm not sure. But until then, I'm completely satisfied with this episode on its own.

Here's a plot that's a mess ... but what an entertaining, well-executed, and absorbing mess it is.

Keep an eye out for my Enterprise season recap sometime this summer.

Previous episode: Two Days and Two Nights
Next episode: Shockwave, Part II

End-of-season article: First Season Recap