The year is 1939. Johnny Thompson has signed on as night watchman aboard the Sea Nymph, a ship that feels less like a scientific expedition and more like a riddle waiting to be solved. His post: the deck of a vessel anchored in tropical waters, surrounded by darkness and the phosphorescent glitter of a sea alive with light. Then he sees it: a green arrow, slicing through the night from a nearby island. Someone is signaling, and they don't want to be found. What follows is classic Golden Age adventure for young readers. The passengers are suspicious from the start: the strange old man with goggle eyes and heavy glasses, the beautiful blonde girl named Doris and her mysterious grandfather, a tall young man whose motives remain unclear. Add to this hints of native unrest along the coast and foreign spies operating in the region, and Johnny's simple night watch becomes a descent into something far more dangerous. The chapters ahead promise underwater discoveries, hidden secrets, and a growing danger that threatens everyone aboard. Snell delivers exactly what adventure readers crave: atmosphere that trembles with threat, a young protagonist worth rooting for, and the slow revelation that nothing on this ship is quite what it seems. For readers who dream of mysterious islands, secret signals, and the thrill of uncovering truth in dangerous waters.
