Emilie & the Hollow World by Martha Wells Page A

some way to detect the traces of aether left behind...” He snapped his fingers. “The aether navigator!” He jumped to his feet, forgetting he still had a sandwich plate in his lap. He caught it agilely before it fell onto anyone's head, and handed it off to Captain Belden. “It should detect the presence of aether, any aether, even a small fragment in the air!”
    Lord Engal dashed off down the corridor to the stairwell, apparently intending to test this immediately. Everyone set plates and cups aside as they hurried to follow.
    In the wheelhouse, Dr. Engal, with Dr. Barshion and Captain Belden, poked at the aetheric navigator, making minute adjustments to its silver wheel, and turning it this way and that. Miss Marlende stood nearby, managing to look over the shorter Dr. Barshion's shoulder, but Kenar stood back at the port, looking toward the abandoned ship.
    Emilie angled around, trying to get a good view without getting in the way or juggling anybody's arm. She finally found a spot where she could look under Lord Engal's elbow.
    Emilie had read descriptions of aether navigators in her favorite sea adventures, but never seen one in person. The aether navigator had a flat silver plate, etched around with the symbols and degrees of the compass directions. Two silver rings could be rotated around it, apparently to help figure longitude and latitude, though Emilie couldn't quite follow how. On the plate itself, in a shallow dish, there was a silvery substance that looked like mercury, but was actually drops of clarified, stable aether. It would roll around as the plate was turned and rotated, pointing the way toward aether currents in the air and water.
    Then Dr. Barshion said quietly, “Wait, wait. I think that's it.”
    “Yes, it's reacting to a concentration of aether somewhere nearby.” Captain Belden carefully marked a spot on the outer ring. “But could it be traces from the airship's earlier movements, when it first arrived at the island?”
    Tilting the navigator's wheel slightly, Dr. Barshion muttered, “I don't think it would remain that long...aether outside a current dissipates relatively quickly. And we know they were here for some time, preparing the balloon to make the attempt to get help from the surface...” The base plate tilted, sending the stable aether skittering around its shallow bowl. He stepped back, shaking his head, grimacing. “I'm sorry, I've pushed it out of alignment.”
    “No, no.” Lord Engal frowned, catching the plate, his big hands unexpectedly gentle as he turned and angled it slightly. “Look at this; it's picking up something on the lower strata. Belden, you know more about surface aether navigation, is that what it looks like...?”
    Belden leaned forward, reading the marks. “Faint traces in the water. Yes, My Lord. It's definitely there. That's going toward the east...” He glanced up at Miss Marlende. “Could the airship float?”
    “Float?” She glanced at Kenar, brows lifted. “I suppose the main cabin might be somewhat buoyant, but I can't imagine that they would try to turn it into a boat. If they had all needed to leave by water, surely they would have taken the Cirathi ship.”
    Kenar came forward, his scaly brow furrowed. “No, there was no plan for that... Perhaps another ship arrived, placed the airship on board, and carried it away.”
    “It would have to be a large ship.” Miss Marlende paced away, shaking her head as she thought it over. “But it would be possible.”
    “Did your people encounter anything like that in this area?” Belden asked Kenar, apparently forgetting how much he disliked him under the excitement of the mystery. “A vessel large enough to transport the airship? Or a settlement capable of building one?”
    “No. In fact, we thought this area was mostly uninhabited.” Kenar pulled the folded square of map out of a pocket inside his shirt and moved over to the chart table to spread it out.
    Oswin put in, “That empty city we