Previouslies: At SFHQ Tam Elbrun proposes an unprecedented alliance among Andorians, Vulcans, Tellarites, and other races not yet convinced about humanity. A monotonous Peter Weller (Robotonous?) calls a Trip/T'Pol crossbreed baby "the most dangerous enemy humanity has ever faced;" armed with a Ravashol Pulsar, he holds them captive on Mars. Meanwhile Malcolm meets a shady type in a dark street, and Travis tracks a sultry spy aboard Enterprise. The story begins as Robotonous blabs insultingly stupid, xenophobic claptrap, that Tam orders shut off. The ambassadors get nervous but do not get packing.

Archer must sneak onto Mars to disable the weapon and rescue Trip, busy misaligning the Pulsar's aim, and T'Pol, busy rocking their baby. In the brig the spy tells Travis she's with Star Fleet Intelligence trying to bust Terra Prime, but he won't be manipulated. Archer has a moment with Hoshi then departs in the shpod to chase a comet (what kind of bad astronomy is this?) though Travis must fly them to the surface on manual after an equipment malfunction (nice touch with the Sojourner rover at the Carl Sagan monument!). T'Pol accuses Robotonous of hypocrisy over his "alien" treatment of his twitching Taggart's Syndrome, comparing him to Colonel Green and appraising him appropriately: "You're not significant."

As the deadline of Robotonous passes Tam orders the Pulsar destroyed but Hoshi won't fire. Archer and his merry men (what, no sharks?) romp across a tremendously terraformed Mars then fizz through a door. Once inside they meet up with Trip, MacGyvering his way out of captivity. Together they confront Robotonous in a mutual countdown sequence, with an acute exchange highlighting the different opinions regarding a crowded galaxy, between Terra Prime ("Not our problem") and Archer ("An opportunity"). The Pulsar fires, blasting San Francisco bay, but all is well as Robotonous expires unexplainably and Archer and Trip escape.

T'Pol names her dying baby after Trip's dead sister; plopping it into an IDIC incubator where neither parent can provide or derive comfort. Phlox screwed up his positive prognosis and now claims incompatible DNA, but still gets to keep his "extra family." The saboteur puts in some Ceti-eel acting before putting a phase pistol point blank to his head. Walking around the crew, Archer speechifies about his generation knowing the answer to "Are We Alone?" He claims, "The Final Frontier begins in this hall. Let's explore it together," and everyone claps slowly like in Star Trek VI. Finally Trip informs T'Pol that their baby died needlessly. A fine symbol of the series!