In this Earth, the ice awoke a couple of million years ahead of schedule, piling on the weight of glaciers in the northern hemisphere, stressing the world with their grinding weight. Where the ice wasn’t present, that pressure forced its way out as volcanic activity across all the fault lines of the world, filling the air with ash and poison. Each time the ice came, it squeezed this Earth tighter in its grip, each interglacial period flipping the world into a harsher, more barren climate. This passes, but it is the crucible that forged our players here.

In Africa there were many primate varieties, big-brained, social, omnivorous. We could look for our near cousins and find the huge and powerful gorilla-forms, along with bands of predatory chimpanzee kin. The latter combine speed and wits with a taste for meat, and have the mental capacity to reap entertainment from ripping a monkey apart. There are monkeys too, and it’s not their story either. Instead, while this Earth was being crushed by the ice and sickened by its own inner fires, there was a species of lemur just smart enough to know it was having a hard time.

The big lemurs are just shy of the chimps in size but in no way able to go toe to toe with them. And they’re brainy, the harsh conditions spurring their intellects into overdrive. A handful of chance mutations also start a cascade of evolutionary advances in communication and social organization. The lemurs come to an awareness of themselves as threatened on all sides and inheritors of a world that’s trying to kill them.

What saves them is community, and an emergent culture that draws very definite lines on the world. They build walls and barriers which declare this as inside and that outside. They learn the scent, fur patterns and facial markings of their kin and declare them us and everything else them. Even when they have hunted their threats to extinction they remember the big cats, the marauding bands of apes; these become the goblins and ogres of their folk tales. And even as the glacial and interglacial periods alternate in their slow dance, this emergent civilization marks out a hundred small polities in equatorial Africa.

Lemur communities replace the forest with monocultures, trees that grow only what they prefer to feed on. But eventually the soil is exhausted, depleted by its denuded ecosystem, and harvests fail. When cupboards are bare, eyes turn to their neighbours’ orchards and plantations. It doesn’t take a lemur genius to work out that it’s easier to spend four days stealing someone else’s harvest than six months growing your own.