Nathaniel squeezed into the navigation station, a grandiose name for the little alcove wedged between the galley and the dining area in the main cabin. He opened the cylindrical cases and laid the charts flat on the canted table, weighting them with tide and pilot books to press the curl out of their edges. Looking for the chart to East Penobscot Bay, he was surprised to find that the old man had included charts for the entire eastern seaboard, forty-one altogether. That could have been another example of his thoroughness, but the wide stiff sheets marked with soundings of coasts Nathaniel had never seen, and with lines of latitude and longitude scribed over waters he did not know, seemed to contain a hidden message. Somehow, merely by touching the charts, he sensed why they had been sent away. He could feel it in his fingertips, as though their father’s purpose was imbued in the ink that colored the land buff and the shoal water pale blue and the ocean depths white.

Opening a drawer under the chart table for the parallel rule and dividers, he got another surprise, and to his mind, it confirmed the message. He pulled the teakwood box out of the drawer and opened it. Inside, nestled in green billiard felt, was the Plath sextant. He hadn’t seen it yesterday. Had the old man put it on board last night? It was German-made, and as beautiful an instrument as ever had been fashioned by man’s hand, possessing a harmony of form and purpose: the aesthetics of precision. “A fine sextant is a moral object,” Cyrus had lectured once. “It will never lie to a sailor, so long as he uses it properly.” And the Plath indeed looked honest and reliable, as certain men looked honest and reliable; it demanded, by its very appearance, to be used properly, the arrangement of its calibrated brass arc with ivory scale, its solid-brass frame and mirrors and sighting scope communicating a kind of rectitude, an intolerance of sloppiness and approximation. The instrument had shot its last sight on Cyrus’s last voyage as a working sea captain in 1879, and had for as long as Nathaniel remembered occupied a place of honorable retirement in his father’s study. He never took it on the summer cruises; a sextant wasn’t necessary for those tame voyages, which seldom took them out of sight of land. The cheap instrument he brought along was mostly used by the boys to practice their celestial navigation. Why would he have given them the Plath if he did not expect them to sail beyond the furthest reach of the brightest beacons? He wanted to make sure they never got lost, and he’d entrusted them with the possession he prized more than Double Eagle herself. The schooner could be replaced; not so the sextant, IN GRATITUDE. ANNISQUAM. DRY TORTUGAS, FLORIDA, MARCH 10, 1879, read the engraved plate fixed to the inside of the box’s cover.