Looking like a pink-flecked, shaven log of a large tree, the bony plug was lifted clear while Seldal, its three spindly legs strapped together so as to minimize bodily projections, was being lifted into Conway’s backpack so that only its long, flexible neck, head, and beak were uncovered. A similar pack containing the instruments and inflatable equipment that both surgeons would use was strapped tightly to Conway’s chest and abdomen. The Diagnostician’s legs were not strapped together, but the sharp contours of its feet were encased in thick padding, and a white, frictionless overgarment was drawn over the limbs and fastened at the shoulders so that only the arms and head were uncovered. A transparent helmet that was free of external projections and large enough to accommodate the necessary lighting and communications equipment was added. Seldal, whose upper body was naturally streamlined, kept its head and beak pressed firmly against the back of Conway’s helmet. The Nal-lajim wore only eye protection and an attachment for the thin air line running into the corner of its mouth.
“Zero gravity in the operative field,” Conway said. “Ready, Seldal? We will now enter the wound.”
A tractor beam seized their weightless bodies in its immaterial grasp, deftly upended them, and lowered them heads first into the narrow opening. The thick cable loom comprising their air supply, suction and specimen extraction hoses, and the emergency rescue line unreeled like a multicolored tail behind them. Conway’s helmet lighting showed the smooth, gray walls of the organic well they had created moving past them, and an enlarged and enhanced image was reproduced on the external display.
“We are at the base of the entry well,” Conway said, “level with the internal surface of the cranium, and have encountered what is probably the equivalent of the protective meningeal sheath. The membrane responds to firm hand pressure, in a way which suggests the presence of underlying fluid, and what appears to be the outer surface of the brain itself lies just beyond. A precise estimate of the distance is difficult because either the membrane or the fluid, or perhaps both, are not completely transparent. A small test incision is being made through the membrane. That’s strange.”
A moment later the Diagnostician went on, “The incision has been extended and opened, but there is still no apparent loss of fluid. Oh, so that’s it . . .”
Conway’s voice sounded pleased and excited as it went on to explain that, unlike in other species of its experience, the cere-brospinal fluid, which helped protect the brain structure from shocks by acting as a lubricant between the inner cranium and brain, was not in the Groalterri species a fluid. It was instead a transparent, semisolid lubricant with the consistency of a thin jelly. When a small piece of the jelly was cut away for closer examination and then replaced, it immediately rejoined the main body without any trace of the earlier incision. This was fortunate since it enabled them to go through the meninges without having to worry about controlling fluid losses, and they could move laterally with minimal resistance and loss of time between the brain surface and the meningeal layer to the first objective, a deep fissure between two convolutions in the area suspected of housing the Groalterri telepathic faculty.
“Before we proceed,” Conway said, “is the patient aware of any unusual physical sensations or psychological effects?”
“No,” Hellishomar said.
For a few moments the main screen gave glimpses of Con-way’s hands and Seldal’s beak, brightly lit by the helmet lamp, as they pushed themselves carefully through the clear jelly between the smooth inner meninges and the massively wrinkled outer surface of the cortex and into the narrow crevice.
“As closely as we can estimate,” Conway went on, “this fissure extends about twenty yards on each side of our entry point and the average depth is three yards. On the upper brain surface the division between adjoining convolutions is clearly evident, but with depth the walls begin to press together. The pressure is not sufficient to be life-threatening, and the effort required to push the surfaces apart is minimal and does not reduce our mobility, but it would seriously hamper any surgical procedure that may become necessary and quickly cause disabling levels of fatigue. Soon we will have to deploy the rings.”