(Two initial messages)

Human evolution had long been described by scientists as advancing in “giant leaps,” yet in truth it crawled forward at a glacial pace.

At least until seventy-one years ago, when a single formulation error tore open a spacetime rift and introduced humanity to other universes and parallel dimensions.

The first universe discovered was remarkably similar to our own, with only a few striking differences—chief among them the nations that stood at the apex of the global hierarchy. There, Africa dominated the rest of the planet.

In the seventy-one years that followed, hundreds of universes were catalogued. Information of every kind was freely exchanged with each of them, yet countless more still waited to be found. Several years earlier a compact personal travel device had already been perfected. Six pieces in total: five metallic wearables—two bracelets, two anklets, and a belt—and a sixth component, a small control pad used to issue commands to the Transdimensional Traveler, or “TT” as it was officially known. Ordinary people simply called it the “Tra-Tra.”

Travel itself was almost absurdly simple. A portal opened, the traveler stepped through the light, and on the far side everything felt as ordinary as crossing a room. The pad displayed the user’s vital signs on the left, the current planet’s parameters on the right, and in the center the coordinate field. One could select from a list of previously visited worlds, each accompanied by its risk percentage. Below that lay the free-entry mode, where anyone could type in random data and coordinates and simply hope. In many cases the portal never opened at all; in others, those who stepped through never returned. A black-list of forbidden coordinates existed for this very reason, permanently locked against reuse.

And now... enter the coordinates and go.

Safe travels.