Described by series cocreator Brannon Braga as "a single episode that lasts 24 hours," the third season of Star Trek: Enterprise is arguably the best in the show's four-season run. With the epic "Xindi saga" as the season's primary story arc, the series found its tonal focus in the unpredictable space of the Delphic Expanse, where alien encounters and matter-warping spatial anomalies forced Capt. Archer (Scott Bakula) to make extreme decisions that tested his ethical boundaries. Realising the need for a fresh viewpoint, Braga and cocreator Rick Berman hired Manny Coto, a TV veteran who conceived or wrote several of the season's finest episodes (not forgetting Mike Sussman and other members of the series' first-rate writing staff). Coto's involvement was instrumental in shaping the Xindi saga, which began (with season 2's cliffhanger) when Earth was attacked by a Xindi probe--a massive weapon which Archer must now destroy. This vital mission dominates season 3, deriving its potent drama from an impressive variety of characters and subplots focused on the five-species Xindi council, which finds its voice of reason in Primate member Degra (season regular Randy Oglesby) and rancor in the Reptilian Commander (Scott MacDonald), pivotal characters whose fates will be tragically intertwined.

Despite lower ratings and budgetary cutbacks (as evident in several ship-bound episodes with minimal casting), season 3 was equally strong as a showcase for the Enterprise regulars, with plenty of fan speculation rising from the sexy and soothing Vulcan "neuro-pressure" sessions between the insomniac Tucker (Connor Trinneer, better than ever) and T'Pol, whose hidden addiction to a toxic compound allows Jolene Blalock to mine the volatile depths of her character (who now sports a more appealing hairstyle and wardrobe). Meanwhile, security chief Reed (Dominick Keating) engages in heated competition with Major Hayes (reliable guest Steven Culp, from the first season of Desperate Housewives), the leader of NX-01's Military Assault Command Operation (or MACO), which Reed views with territorial suspicion. And while Enterprise still fumbled to develop the characters of Hoshi (Linda Park) and Travis (Anthony Montgomery), John Billingsley continued to bring clutch-player excellence to his role as Dr. Phlox in several highlight episodes including "Doctor's Orders" and "Similitude," the latter featuring equally strong work by Trinneer in an ethically complex (and fan-favorite) examination of the cloning--a typical example of Star Trek at its best.

The alternate timeline of "Twilight" also honours the classic Trek tradition, while "Harbinger" reveals the existence of the trans-dimensional Sphere Builders, whose moon-sized creations affect Enterprise throughout its season-long mission. Finally, the crucial appearances of blue-skinned Andorian Shran (Jeffrey Combs) bring both suspense and comic relief to the season's grim proceedings, adding depth and tentative alliance to Enterprise's pre-Federation politics--a crucial element that assumes greater importance with the jaw-dropping cliffhanger of "Zero Hour" and the surprises in store for season 4, which will bring Enterprise ever closer to the original Star Trek timeline.