Fragment

9:31 P.M.

The moon floodlit the cove outside the porthole of his room while he organized his gear.

Dante chose to use a minimal rack, rigging his Black Diamond climbing harness and gear slings with nuts, cams, carabiners, and a number of gri-gris. Then he tied together six sixty-meter pitches of Edelweiss dynamic rope for the solo climb.

He checked the Voyager Lite camera and transmission backpack he had stolen from SeaLife’s stowage compartment. The battery meters read nearly full, and the Night Vision switch brought up the expected greenish display. He located the transmit button, easily reached on the backpack.

He stowed the backpack, rope, and climbing gear in a five-foot-long waterproof duffel bag. Then he hoisted a body-surfing raft he had brought along so he could sneak the equipment ashore below the Navy’s radar.

The full moon hung directly overhead as he slipped into the sea from the stern, beside the large Zodiac, placing the bag of gear on the raft. Once in the brisk water, he slipped on a pair of swim fins. Then he paddled quietly to shore with the tide, conserving his leg muscles.

Nell gazed out the window of Section Four, studying the glistening nocturnal grazers as they sprouted in the moonlit field. What kind of symbiont could alternate its chemistry to feed on so many different sources of nutrients? she wondered. She rubbed her forehead as she turned the problem over in her mind.

Andy studied Nell. “What are you thinking?”

“It’s not lichen.”

“OK. So what is it, then?”

“I’m not sure…The top growth rate of lichen is about one or two centimeters a year. The stuff on these fields grows faster than bamboo. Its geometric growth pattern reminds me of Ediacara fossils, some really primitive organizations of single-celled life. Whatever it is, it seems to be the base of the food chain here.”

“If it’s not lichen, what is it?”

“Let’s call it clover. The clover photosynthesizes by day and eats rock by night-and these grazers come out at night to eat the clover. Maybe the grazers prefer the minerals the clover consumes at night, or don’t like chlorophyll… We know that some green algae in birdbaths turns red to protect itself from too much light or salinity-but it takes days to make that color change…”

“Hmm…”

“But we know lichen is a symbiont formed from algae and fungus.” She opened her eyes and looked at Andy, but her focus was distant and inward. “In lichen, the algae provides oxygen and organic molecules like sugars and ATP through photosynthesis. The fungus helps dissolve rock and provides nutrients for the algae to synthesize organic molecules.” She focused on Andy. “You with me?”

“Sure!”

“OK, so now-what makes this clover turn purple? The only thing I can think of is purple bacteria.” She looked out the window as though she could suddenly see through a fog. “This may be a symbiont of cyanobacteria and proteobacteria, which uses sulfur as an energy source-and turns purple! There’s a lot of iron sulfide, fool’s gold, on the island. I noticed it on the beach…So if this is some kind of cyano-proteobacteria symbiont, then the purple phase of this stuff would produce hydrogen sulfide gas-and stink like rotten eggs, like Zero mentioned! But during the day, when photosynthesizing, it would produce oxygen… while the sulfur-reducing bacteria might retreat underground…”

She leaned forward, intently watching one of the nearest fernlike creatures pressing down a translucent frond on the field. White smoke curled around the pads at the end.

“Of course!” She looked at Andy with wide eyes as three thoughts slammed together in her sleep-deprived mind. “If those ‘grazers’ only come out at night, they may be so ancient that they have to avoid oxygen! They may need the hydrogen sulfide gas to protect themselves and re-create the primordial atmosphere that they evolved in. See?”

“Go on, go on!”

“And if these grazers eat this stuff when it’s purple, they could be ingesting purple bacteria like Thiobacillus to convert the hydrogen sulfide in the plants into sulfuric acid-which they may be using to scour the clover off the rocks!”

“Nell,” Andy gasped. “You’re amazing. I don’t have the slightest idea what you just said, but it’s amazing! I told everyone down in Section Two you thought it was lichen, so they’re all calling it lichen now. Sorry.”

She laughed wearily. “That’s OK, Andy. It’s hard to believe this is even our planet. I’m glad we’re here, though. If I couldn’t do something after…I think I might have gone crazy on that ship.”

“Yeah. I think they call it survivor’s guilt.”

“No.” Anger instantly erased the humor from her face. “If survivors do something about it, there’s no reason to feel guilty, Andy. Unless they don’t.”

“It’s up to the living to avenge the dead, eh? Isn’t that how the saying goes?”

She stared at the darkening jungle below, thinking of her eleven shipmates that were now gone. “Something like that,” she answered softly.

“But can you take revenge on animals, Nell? After all, we were the ones who intruded on them. Animals can’t help what they do. They didn’t have a choice. I know what happened to your mom, Nell, but-”

Her eyes scalded him.

“OK.” He nodded, and backed off. “I’m sorry.”

She looked back out the window, focusing on the glistening creatures emerging across the purple slopes of the island.

Glowing swarms of bugs came out of the tangled vegetation now and swirled across the fields in clusters as they grazed.