Morgan's late-night experiments with the lighthouse signal were supposed to cure the boredom of a lonely posting—flash a pattern into the dark water, see if anything flashes back. But something did flash back, perfectly mimicking every sequence, and now Morgan can't stop the nightly conversations with whatever intelligence lurks in the depths. When cargo ships begin vanishing without distress calls in the surrounding waters, Morgan realizes the communication might have been a terrible mistake. The coast guard is asking questions, the patterns from below are becoming more complex and insistent, and Morgan must decide whether to confess to possibly causing an international maritime disaster or dive deeper into a dialogue that was never meant to happen. Some conversations should never be started—especially with things that live where light dies.