Life didn’t just have to evolve.

It had to survive the end of the world—over and over again.

In Episode Six, we confront the darkest truth of our origin story: Earth is not merely a cradle for life, but a gauntlet. A planet that repeatedly reset the evolutionary clock through catastrophes so severe they nearly erased the experiment entirely.

These events are known as the Great Filters—moments when most life fails, complexity is wiped away, and only a few fragile lineages slip through to try again. From global ice ages to poisoned oceans, from volcanic hellscapes to asteroid impacts, Earth has tested life with indifference bordering on cruelty.

We trace the great mass extinctions that reshaped the biosphere:

• Worlds frozen and suffocated

• Seas stripped of oxygen

• Continents burned by volcanic fire

• Skies darkened by falling mountains

Each time, dominant species vanished. Entire evolutionary futures were erased. And each time, unlikely survivors inherited a radically altered planet.

Dinosaurs didn’t fail—cosmic chance ended their reign. Mammals didn’t triumph through superiority—they survived by luck, timing, and small size. Our existence is not the result of a straight line of progress, but of repeatedly not being eliminated.

This episode places Earth’s history in a cosmic context, linking mass extinctions to the deeper mystery of the universe’s silence. If intelligent life is rare, perhaps it’s because most worlds never make it through their filters.

And then comes the unsettling realization:

For the first time, one of the Great Filters may not be behind us.

For the first time, the catastrophe has a face.

And it looks like us.