If the first two nights of Syfy’s epic return to straight-faced genre fare, Childhood’s End, felt at turns either redundant or slightly too ridiculous — like any line spoken by Ricky Stormgren — the series’ final and most sweeping section justifies the rest. The third part, is a uniformly enjoyable piece of science fiction, ambitious and weird and fun and overwrought in all the right places, and enhances the rest of the show retrospectively.

We figure out, early on, what the basic plan is for Earth, though Karellen will iron it out a couple more times before the hour and a half is up. Amy and Jake Greggson’s green eyed baby, Jennifer — the Overmind’s name, not theirs! — has become a legit horror-movie-ready 8-year-old, and draws flocks of children to her doorstep in a segment that feels like an embedded X-Files episode. “Jennifer” is God and the devil on Earth at once, compelling babies around the world to draw their bottles to them from the other end of tables by sheer force of will. Toddlers in France mutter her name and stare wide-eyed toward the sky. Sacré bleu!

Eventually, it’s all too clear: The children are not what they seem, and the adults of the world are living on borrowed time. Eventually, the kids levitate skyward like hellish cherub-angels, taking the place of the Overlord’s ship and hovering above Earth. It’s an indelible image — the best in the series.

Any narrative in which you know that the world is going to end has a potent, unique effect. Think Dr. Strangelove, Melancholia, or A.I — you view everything leading up with it from a weird, slightly cold distance. Character-building, emotional moments feel gestural — futile, absurdist flourishes in a much bigger, perpetually ungraspable narrative. This feeling of cryptic inevitability passes over us powerfully when Ricky Stormgren succumbs to the alien cancer that slowly branches out all over him, and after Amy and Jake give into self-destruction after making a last break for spiritual freedom to New Athens (the NYC stand-in and Earth’s last “free” zone). Everyone is a symbolic archetype, like the semi-Biblical figures they are supposed to be. That’s why it kind of works that no one except Charles Dance is much of an actor.

Once Clarke’s plot really gets set in motion — in the series, the Overmind’s apocalyptic plan, for which Karellen and his race are only the “facilitators….midwives, if you will” — a whirlwind of gripping cause and effect unfolds. Amidst it, Milo — ever-curious but now also trying to save the Earth from failure — manages to steal away in a spaceship, vacuum-sealed and in hibernation mode. Everything is happening too fast for any one of these people to matter, and they gracefully settle into their role as ciphers and symbols. The dizzying special effects ramp up, and with them the associations with every other classic sci-fi saga or speculative dystopian fiction you’ve ever heard of.

The commonality is not a bad thing. It simply feels like Childhood End’s creators know exactly the beats they have to hit, and the kind of series they are making. But thank God, they aren’t winking about it.

Eventually, Milo, eighty Earth years into space, confabs with the Overmind (the God-like intelligence at the heart of the universe), a broken-English-speaking Karellen look-alike at the aliens’ home planet, and eventually Karellen himself. He’s the one human left alive to comprehend fully, as well as any being can, the secret of existence. It turns out that Earth is one of many words the Overmind has designed to put to rest a similar manner. But Milo, in his last hours, clings to kernels that remind him that his planet was different, not just one of a hoard. “You ever come across a civilization with cookie dough ice cream?” he asks Karellen, who responds in the negative. “We did that,” Milo says tearily, looking at the charred Earth from out the spaceship window.

Sure, it’s serious bathos, but what a perfect bit of poignant denouement for a show that has successfully built a universe that is so much bigger than the sum of its little, overly earnest parts. You don’t expect anything less, and in the moment, Milo’s quip is pretty moving. Childhood’s End has managed to shift its goal posts exactly where it wants them to be; you, the viewer, are connected to its Overmind, and taking its cues. In that context, lines like that work.

You ever come across Syfy original programming as good and gripping as ‘Childhood’s End’? “No,” Karellen would nod solemnly. Syfy is back, and let’s hope they continue this hot streak with future on-brand ventures.