21 ::: Dennie and Toshio

Dennie checked the charges one more time. It was dark and crowded in the close passage of the drill-tree root. Her helmet's beam cast stark shadows through the thick maze of rootlets.

She called upward. "Are you almost finished, Toshio?"

He was planting his explosives in the upper section, near the surface of the metal-mound.

"Yeah, Dennie. If you're done, go back down now. I'll join you in a minute."

She couldn't even see his flippered feet above her. His voice was distorted in the narrow, water-filled thicket. It was a relief to be allowed to leave.

She picked her way downward carefully, fighting back waves of claustrophobia. This was no job Dennie would ever have chosen. But it had to be done, and the two dolphins were by nature unqualified.

Halfway down, she snagged herself on a strand of creeper. It didn't let go when she tugged. Thrashing only entangled her further, and she vividly recalled Toshio's story of the killer weed. Panic almost closed in, but she forced herself to stop kicking, to take a deep breath and study the snare.

It was just a dead vine wrapped around one leg. The strand parted easily under her knife. She continued her descent more cautiously and escaped at last into the grotto beneath the metal-mound.

Keepiru and Sah'ot waited below. Hose-like breathers covered their blowmouths and wrapped around their torsos. The headlights of the two sleds diffracted through thousands of tiny threads that seemed to fill the chamber in a drifting fog. A dim light filtered into the grotto from the cave mouth through which they had entered.

* Echoes sounding, in this rock-cage

Will not be those of happy fishing *

Dennie looked at Sah'ot, unsure she had understood the poet's fancy Trinary.

"Oh! Yes. When Toshio sets the fuses, we'd better get outside. The explosion will reverberate in this chamber. I don't suppose that would be healthful."

Keepiru nodded in agreement. The expedition's military commander had been mostly silent all the way here from the ship.

Dennie looked around the underwater cavity. The coral-like, microscopic scavengers had built their castle on the rich silicate rocks of an ocean hillock. The structure had grown slowly, but when the mound finally breached the ocean surface toplife became possible. Among the vegetation which had sprouted was the drill-tree.

That plant somehow pierced the mound's metal core and penetrated to the organically useful layer beneath the island. Minerals were drawn up and deposited above. A cavity grew below, which would eventually accept the metal-mound into the crust again.

Something struck the ecologist in Dennie as odd about this arrangement. The tiny micro-branch Library aboard Streaker hadn't mentioned the metal-mounds at all, which was curious.

It was hard to believe the drill-tree could evolve into its niche in a gradual way, as most species did. For the tree to succeed was an all-or-nothing proposition, requiring great power and perseverance. How did it get that way? Dennie wondered.

And what happened to the mounds after they fell into the cavities the drill-trees prepared for them? She had seen some pits which had swallowed their mounds. Their depths were cloudy and obscure, and apparently far deeper than she would have expected.

She shone her beam on the bottom of the mound. The reflections were really quite startling. Dennie had expected something ragged and irregular, not a field of bright concave pits on the shining metal underside.

She swam to one of the larger depressions, bringing up her camera. Charlie Dart would like to get pictures and samples from this trip. She knew better than to expect thanks. More likely each tantalizing photo or rock would send him into exasperated sighs over her failure to follow up obvious leads.

Deep within one of the pits something moved, a twisting and slow turning. Dennie re-oriented her beam and peered closer. It was a root of some sort. She watched several of the tiny drifting threads fly within reach of the hanging tendril, to be caught and drawn within. She grabbed at a few for her sample bag.

"Let's go, Dennie!" She heard Toshio call. There was a thrumming sound as a sled moved just beneath her. "Come on! We've only got five minutes till they blow!"

"Okay, okay," she said. "Give me a minute." Professional curiosity momentarily overwhelmed other thoughts. Dennie could think of no reason why a living thing should burrow into the lightless underside of a mass of almost pure metal. She reached far into the pit and grabbed the twisting tendril root, then braced herself against the bulk of the mound and pulled hard.

At first the springy root was adamant, and seemed even to pull back. The possibility that she had trapped herself vividly occurred to Dennie.

The root tore free suddenly. Dennie glimpsed a shinyhard tip as she stuffed the specimen into a sample bag. She flipped and kicked away from metal surface.

Keepiru looked at her reproachfully as she grabbed the sled. He gunned the machine toward the cave entrance and out into the daylight, where Toshio and Sah'ot waited. Moments later a loud concussion sent booming echoes through the shallows.

They waited an hour, then re-entered the grotto.

The charges had shattered the drill-tree trunk where it pierced the bottom side of the metal-mound. The severed shaft canted at an angle below, continuing down into murky depths. Bits of debris still fell from the opening in the mound's bottom. The chamber below the island was thick with swirling shreds of vegetation.

They approached the opening cautiously. "I'd better check it out with a robot first," Toshio said. "There may be unstable chunks left in the shaft."

* I will do this — ladder runner

* Robots heed my — close nerve socket *

Toshio nodded. "Yeah, you're right. You do it, Keepiru." The pilot, with his direct machine-nerve interface, would be able to control the probe better than Toshio could. Of the humans aboard, only Emerson D'Anite and Thomas Orley had such cyborg links. It would be a long time before most humans could deal with the side effects of socket implantation as well as dolphins, who had needed the interface far more and had been bred for it.

Under Keepiru's direction, a small probe detached itself from the rear of the sled. It jetted of toward the hole and disappeared within.

Toshio had never expected to be sent right back out again with Keepiru — to a site where, in his opinion, neither of them had behaved particularly well. The importance of their mission, to serve and protect two important scientists, confused him even further. Why didn't Creideiki assign someone else? Someone more reliable?

Of course, the captain might have ordered all four of them out of the ship to get them out of his way. But that didn't seem to fit either.

Toshio decided not to try to pierce Creideiki's logic. Inscrutability seemed to be at the heart of it. Perhaps that was what it was to be a captain. Toshio only knew that he and Keepiru were both determined to do a good job on this mission.

As a midshipman he officially outranked Keepiru. But tradition made warrant officers and pilots masters of middies unless otherwise decided by higher authority. Toshio would be assisting Dennie and Sah'ot in their studies. On security matters, Keepiru was in charge.

Toshio was still surprised to find that others stopped and listened when he made suggestions; his opinions had been routinely solicited. That alone would take some getting used to.