“You can’t control a living thing without destroying what’s alive about it” — Zor-El
That quote is key for Superman Unbound, as Superman deals with a new threat to Earth, a threat from Krypton’s past that threatens the galaxy at large in addition to his adoptive home. Brainiac travels the universe capturing cities in bottles and then destroying their planet of origin, in an attempt to absorb all the knowledge in the universe. In order to prevent new knowledge from existing, Brainiac keeps the cities in the same state they were when they were captured. No one ages, everything stays the same, they are trapped in purgatory. As you can imagine, Superman is not okay with this fate befalling Earth, nor is he fine with leaving the lost Kryptonian capital of Krandor as a bottle decoration in Brainiac’s ship.
Superman: Unbound is based on Superman: Brainiac by Geoff Johns and Gary Frank. Brainiac presented here is a cold, calculating monster that is an unstoppable force in the galaxy. He’s been at it for decades, adding city after city to his collection and leaving a trail of death and destruction in his wake. Brainiac brings up echo of the Borg, as he arrives in a lone ship (though his is shaped like a black skull), his robot troops adapt to the local defenses and absorb the knowledge of his victims. They both carve out cities from the ground, and Brainiac is more machine parts than organic at this point. But he’s also just one guy, as opposed to a collective consciousness. The motivations are similar but also different.
We begin with seemingly normal situations on Earth, massive violence in Metropolis (committed, they say, because Superman will obviously be busy with an earthquake in South America that happened a bit ago!) The heavily armed thugs manage the best the surprisingly militarized Metropolis police, but what they don’t bank on is Supergirl showing up to ruin their fun. Lois Lane (who volunteered to be their hostage) provides the snark as Supergirl rips through their defenses, joined by Superman, who faster than a speeding bulleted his way back to the US in time to take out the last of the bad dudes.