For most of the night, the scene was replayed, the surgery swaying gently with the water below. The chirurgeon slept a little, periodically checking Tanner’s progress, and that of the slowly dying cod suspended in a matrix of thaumaturgic strands that dragged out its demise. He applied pressure when it was needed, changed the settings of finely calibrated gauges, added chymicals to the sluicing water.

In those hours, Tanner dreamed of choking (while he opened and closed his eyes, unknowing).

When the sun came up, the chirurgeon uncoupled Tanner and the fish from his machinery (the cod dying instantly, its body shrunken and wrinkled). He closed up the flaps of skin in Tanner’s neck, slimy with gelatinous gore. He smoothed them down, his fingers tingling with puissance as the gashes sealed.

Without Tanner waking-still drugged as he was, there was no danger of that-the chirurgeon placed a mask over Tanner’s mouth, sealed his nose with his fingers, and began to pump brine gently into him. For several seconds there was no reaction. Then Tanner coughed and gagged violently, spattering water. The chirurgeon stood poised, ready to release Tanner’s nose.

And then Tanner calmed. All without waking, his epiglottis flexed and his windpipe constricted, keeping the saltwater from entering his lungs. The chirurgeon smiled as water began to seep from Tanner’s new gills.

It came sluggishly at first, bringing with it blood and dirt and scab matter. And then the water ran clean and the gills began to flex, regulating it, and it pulsed across the floor in measured draughts.

Tanner Sack was breathing water.

He woke later, too vague to understand what had happened, but infected by the chirurgeon’s enthusiasm. His throat hurt terribly, so he slept again.

That was by far the hardest thing done.

The chirurgeon peeled back Tanner’s eyelids and bound to him clear nictitating membranes taken and modified from a caiman bred in one of the city’s farms. He injected Tanner with particulate life-forms that thrived in him harmlessly and interacted with his body, making his sweat a touch more oleaginous, to warm him and slide him through water. He grafted in a little ridge of muscle at the base of Tanner’s nostrils, and little nubs of cartilage, so that he could flex them closed.

Finally, the chirurgeon performed by far the easiest, if the most visible, alteration. Between Tanner’s fingers and his thumb, he stretched a membrane, a web of rubbery skin that he pinched into position, tethering it in Tanner’s epidermis. He removed Tanner’s toes and replaced them with the fingers from a cadaver, sewing and sealing them onto Tanner’s foot until he looked simian; then he changed the resemblance from ape to frog as he stretched more webbing between those once-more living digits.

He bathed Tanner, washed him in seawater. Kept him clean and cool, and watched his tentacles writhe in his sleep.