Even at a distance in the hazy daylight, Sylvana could see Captain Ruggero Barsetti frowning at her as she walked down the dock carrying her diving suit. It was easy to read his thoughts: Her belly was growing, and it wasn’t seemly for her to be working so hard.

“What are you doing here, little one?” he said gruffly. It wasn’t his usual custom to be tender.

“I’m going out to Gate 38. Giorgio reported that something was causing it to snag. He could see it on his sonar on the big boat, but he didn’t have a diver. If it turns out to be a building, we are going to have our work cut out for us. Another big incursion is coming.”

“I appreciate your dedication, but I am aware of the gate problem,” the Captain retorted. “We are working on it. You should just go on home and take it easy until the baby arrives.”

Sylvana looked down at her calloused hands. “You know I can’t do that, cugino,” she said to her older cousin. “If I quit my job, I’ll never get back on. I’ll soon have another mouth to feed now, you know.”

“You’re a member of the clan. We’ll take care of you,” Ruggero said. He added, “Have you thought of joining the farming initiative after the baby comes?”

“And what will we use for fresh acqua? The only measurable rainfall is out over the sea. No, I don’t think the farming is going to happen soon.”

The Amborgettis were building freshwater collection platforms several miles offshore, but it was a risky venture in her view. The storms could be ferocious, and it was still too dangerous to subsist out on the exposed ocean. She’d stick with diving salvage from old buildings.

Sylvana felt a little guilty about playing the baby card, but she was the chief diver for the Barsetti clan. Maybe someday she could take it easy if the new farming project got off the ground. Or on the ground. There would be plenty of easy work then dusting off solar panels, to funnel back energy and provide additional light for the crops. But for now she had to keep her independence with Franco gone.

Sylvana and her relatives lived, barely, in one of the few coastal cities on Earth to survive the Gemini, the twin extinctions. The first disaster was widespread starvation initiated by runaway global warming. People moved from drought-stricken areas to the continental shores, only to fall victim to flooding and tsunamis. Then, as if humanity were not facing trials enough, an untracked extra-solar system ice ball struck Mexico in nearly the same spot as an asteroid had 66 million years ago. Any species unable to live on sludge, worms, and detritus had a difficult time in the aftermath.

Fortunately, humans are omnivores, and Sylvana’s scavenger ancestors had been fairly clever about turning dead plant and animal material into foodstuffs for people. Also luckily, there were a lot fewer people who needed to be fed. Those living in what remained of southern Europe clustered around Tristezza, or Trieste, as the Italians used to call it half a millennium ago. Now the name simply meant “sadness.”

Since the Gemini, Tristezza had watched its sister city across the Adriatic slowly succumb to the rising sea levels. Venezia had battled encroaching waters from the surrounding blue Adriatic Sea for centuries, and spent multiple fortunes hiring Dutch engineers to remove river silt and hold back the tides that threatened to overwhelm its lagoons. Venezia’s MOSE, with its series of gigantic steel sluice gates anchored below the surface, was a wonder of the world. When high tides threatened, the gates would float to the surface to protect the city. But after the Gemini, Venezia’s population dwindled, and, sensing a bargain, Tristezza negotiated to buy, dismantle, and move Venice’s gates to its own waterfront. Then the ocean erased any other signs of the great city.

Sylvana’s clan all worked to preserve the coastline and maintain the gates of Tristezza. Another clan, the Amborgettis, was responsible for running the pumps that constantly filtered the Adriatic waters for food and potable acqua. Although the climate had cooled considerably, the Adriatic Sea’s low salinity and moderate temperatures provided a climatic refuge for the remaining human population.

Sylvana’s scientist husband, Franco, had spent most of his life aboard sailing ships that Tristezza sent out each year, traveling around the boot of Italy and up the Ligurian Sea, looking for pockets of surviving species that might be suitable for refilling ecological niches or providing sustenance for humans. Franco had died five months earlier when his ship Santo Antonio tragically sank on the rugged Cinque Terre coast. Everyone thought it must have been in one of the aftershocks that continued to radiate across the ocean bed. Icelandic volcanoes regularly spewed ash and sulfuric acid into the atmosphere, cooling and darkening the hemisphere.

The argument over for the moment, Sylvana donned her suit, while the captain waved to Giorgio to bring the rowboat closer to the dock. The Barsettis owned 16 boats of varying sizes, all created from digital models and constructed of liquid plastic.

Giorgio rowed with one of the plastic oars and nosed the boat up, holding it steady so that Sylvana could step in.

Sylvana flashed a smile and clambered aboard. She sat near the prow to monitor the echo locator, perching her helmet in her lap. To save fuel, Giorgio made the two-mile row out to the gates. Sylvana silently counted his strokes to estimate when they were close to the 38th sluice. The sea was a touch choppy today, making it a bumpy ride.

As the water slapped against the sides of the boat, she unsnapped a long telescoping pole from the interior wall and unfolded it over the water. Giorgio rowed in a tightening circle, while Sylvana poked into the murky water. The tide was not yet officially an incursion, so it should be low enough that she could find the gate without having to try to inflate it with compressed air.

Ah, luck was with her. Her pole hit something solid.

“Let’s stop here, Giorgio,” she said. Her red-bearded oarsman tossed over a heavy anchor, which would slow them down, although the rope wasn’t always long enough to reach the sea bottom. The rope would be her lifeline if she was unable to see the surface, which was most of the time.

Sylvana tucked in her long braid, as Giorgio helped her don the helmet and twist the air hose onto the valve. She slipped into the chilly water and began descending the anchor rope. As the surface closed over her, she could see only a bit of pale sun overhead. It was a short journey to the obstruction they had located. She could barely make it out with her torch, but it appeared to be part of an old wooden dock from the original Trieste marina that had slipped under water about 80 years ago. It should have floated out to sea, but part of it was stuck about 50 feet below the surface, maybe on one of the gate pylons. Chunks of plastic and other trash were accumulating on the obstruction. She pried a piece loose and tucked it into her catch bag.

She tugged on one of the timbers, but it didn’t budge. She would have to surface and get more rope. And more help. Maybe with two or three boats they could dislodge it and pull it inland. Wood was a valuable commodity, even if waterlogged.

Sylvana’s efforts to move the dock kicked up a dark green slow-motion cloud, probably dead algae that would have been useful as food, except that now she couldn’t see anything. She swam around for a while without finding the boat. She reminded herself not to panic and hyperventilate. After what seemed like an eternity, she heard Giorgio pounding on the rowboat hull. She swam in what she hoped was the right direction and with relief grabbed the anchor rope.

Giorgio pulled her in, and said, “What took so long? What did you find?”

Exhausted, Sylvana began shedding her suit. She noticed that Giorgio stared a little, and was a little embarrassed that he probably was looking at her expanding stomach. She started to tell him about the submerged find, but suddenly she felt queasy, and spots swam before her eyes. She sank toward unconsciousness, and the last thing she remembered was Giorgio shouting soundlessly as he struggled to pull up the anchor.