(You’ve long had this belief that this is what will happen when you’re at last to descend. It will take your sphere a long time to go down. At first, at the surface, it’ll snap and pitch, ungainly, and every wave will fuss it. But when the pumps start and the whirr of engines begin it’ll move urgently down, out of the light. The window will sweat condensation as visibility diminishes.

You’ve long felt that, in a fashion, you will be met. That is to say this:

If you’re lucky or have a say the journey will be close enough to the flank of some submerged cliff, that with the occasional blast of cold arc lights you’ll see the face of earth and the corals close to you. Perhaps the attentions of cold unstartled animals. So you’ll go down into this notional trench whispering into your recorder so you can later hear what a voice sounds like half a mile down. Descending beyond the level of the seafloor thereabouts towards a crack. But what will happen is something other than that swell behind the ribs occasioned by first arrival that you’d have thought you’d be expecting, your heart soon to stir instead because of having been preempted.

At the limits of your light, a few metres before the journey ends, you’ll glimpse a figure on a ledge. A dark-glassed helmet and segmented limbs. Armour, metal and rubber and thick glass, of antique design. Tubs of old air, or airlessness now, strapped to a barrel-broad chest. Complex filigree of decorative details on the porthole. A style of which you recognise nothing but its age. Legs sitting straight-kneed looking out into the black like a child at rest after a game. It will have been thus for many lifetimes.

You’ll see it below your window on your way and then beside you and then above, quickly, but you’ll still be sure of what you saw. Without a word, so as not to alert your companion in the craft—this being a communion you’ll claim for yourself—you’ll salute that vanguardist who in their death has made you a promise and told you a secret. You and only you will know of a prehistory of women and men committed to the descent.

Maybe what you’ll have seen is empty, dropped and fallen to rest in a chance attitude of placidness. But there’ll more likely be bones within, pioneer bones. You’ll know that.

More: you’ll know without proof that the person stopped at their overlooking point not on the way down but the way back up again. Surely that was perhaps a grappling hook beside them? Rope and chains on their shoulder, already worn? When you watch the hagfish worry at the base of the world, they’ll do so on striae of slime and silt themselves layered above the print of a caulked hobnailed boot.)