It was a fat metallic teardrop, slightly elongated, its LTA attachment eyelets extending along the top in a double ridge reminiscent of the backbone of an antediluvian Earthside monster. The principle was relatively simple. Most of the external sub was carrier for the plaz globe of the gondola at the core. Only the drive motors and fuel storage were made strong against the sea’s pressures. The carrier had one more important function now visible to her eyes: Vertical lines of plaz-bubble lights extended up and down its sides—each bubble four centimeters in diameter. The trigger system to light them in sequence passed through a computer/sensor feedback program. What the sensor-eyes saw in the ocean depths, these lights could play back. The kelp’s patterns would be its patterns, the kelp’s rhythms its rhythms.

The chief of Construction Services, Hapat Lavu, came out to meet them at the edge of the lighted area. He was a slender, driving man, completely bald. His gray eyes missed few details of his work and, despite a biting and accusatory tongue which delivered reprimands with thin-lipped fury, he was one of the best-liked Colonists. The common assessment was, “You can depend on Hap.”

Dependability gained high marks groundside, and Hap Lavu was fighting for his reputation. Of all the equipment from his shops, only the subs had failed to match Pandora’s demands. Sixteen had been lost without a trace—there had been survivors from four, and the wreckage of three others had been located on the bottom. All had been crushed or otherwise disabled by giant strands of kelp.

Lavu’s assessment was the opinion of many: “That damn stuff can think and it’s a killer.”

He had become an admirer of Thomas during their short association. Thomas had taken the accepted sub-components and reworked them into this new design. The only parts of the plan Lavu distrusted involved communications and pickup. He spoke to that as he greeted Thomas: “You should have something better than the rocketsonde. They fail, y’know.”

“We’ll stick with it,” Thomas said.

He knew what worried Lavu. The ubiquitous ’lectrokelp not only clogged the seas, but their electrical activity jammed the communications channels—sonar to radar. Hylighter exhibited similar phenomena. Was there a relationship? There was no pattern to the jamming; it was random squirts of signal activity. Because of this, they depended on high power and line-of-sight relays waterside. Even then, a cloud of hylighters rising from the sea could block transmissions.

“You’ll have to surface before you can communicate,” Lavu said. “Now, if you’d let me adapt the anchor cable to . . .”

“Too many lines to the sub,” Thomas said. “We could tangle in them.”

“Then pray that y’can lift above interference for the relays to take your talk-talk.”

Thomas nodded agreement. The plan was to anchor the LTA in a lagoon, slip down the anchor cable in a vertical dive and stay clear of the kelp barriers.