Shetland, 1868.

After a brutal winter of poor catches and mounting debt, eight fishermen sail aboard the aging Mercy toward the waters beyond the Faroes. Captain Magnus Halcrow promises that one rich haul could save their families from another season of hunger.

Then the sea gives them more fish than any of them have ever seen.

The abundance is wrong.

Soundings find a bottom where no bottom should exist. Something vast moves beneath the shoals. And when it finally rises, the Mercy is left dismasted, leaking, and stranded far from shore.
What will happen to the crew and what will be left of them.