Terminator: The Sarah Connor Chronicles
"He's not a solider," warns Sarah.

"No. Not yet," responds Derek.

Therein lays an increasingly dominant theme to Terminator: The Sarah Connor Chronicles as it delves into its second season. We know what John Connor is to become. Now we see him taking steps toward that destiny.

This week's episode finds a "triple-8" honing in on Martin Biddel, another of those modern-day civilians who, says at least one version of the future, will play a large role in the war against the machines. The catch, as we saw in the very first Terminator movie, is that one or two innocent Martin Biddels may have to die along the way as the "right" one is hunted. (The triple-8s, for all their advances, apparently do not Google very well.)

As the hour unfolds, it brings to light the reasons why Terminator works as an ongoing series:

Destiny Awaits
To protect one Martin, John must enroll in military school, significantly symbolizing his getting closer to that aforementioned fate. Watch for a moment at the shooting range where the lad's "unorthodox" upbringing reveals itself.

Favorite Uncle
Derek, also "undercover," has John's back at the presidio, underscoring one of this season's strongest components — the ersatz father-son dynamic between Thomas Dekker and Brian Austin Green's characters. (BAG, in fact, has an outstanding scene as he makes one kill-happy student recoil with a tale of the reality of war.)

Sarah's More than "One Tough Mother"
She's also a nurturing mother, as she and Cameron do their best to protect another, very young Martin from termination — even if doing so means making difficult, sometimes unethical decisions.

The Redhead Is on Fire
Shirley Manson not only makes for one of the franchise's most interesting-looking Terminators, her Catherine also gives a much-needed "face" to the machines' over-arching mission. Usually, the tin cans only have killing on their mind. Catherine, though, is crafty and corporate-minded, which may be the most lethal combo of all.

The Future Is Shocking
The Terminator movies flashed forward long before it became avant garde on the small screen, and to this day it is still to great effect. Each time Derek glimpses at what's to come, resistant fighters huddled in a shaky bunker with metallic creaking and rat-a-tat-tats filling the air, we are reminded of what is at stake in the survival of both John and his father (played by Jonathan Jackson).

Tonight's hour concludes with an emotional twist as Martin's ultimate significance — should he survive the present — is brought to the fo