The novel follows the adventures of Gregory Ashford, a boy kidnapped as a child from his village along a river and forced to join the crew of the legendary pirate ship Wild Wind. Guided by Captain Iskra, Gregory grows up amidst raids and battles, learning to survive in a ruthlessly harsh world. After years of adventures in the Southern seas, Gregory lands in Madagascar, where he allies with the local king and falls in love with Princess Ravina. Here, he discovers the existence of an ancient treasure protected by a curse. Through puzzles, betrayals, and struggles for power, Gregory finds himself forced to choose between wealth and the fate of Madagascar. Centuries later, his descendant Isabelle Ashford, driven by the family legend, begins a quest to find the lost treasure, uncovering secrets that will forever change her life. Amidst intrigues, conspiracies, and a cursed legacy, The River and the Sea weaves epic piracy and historical mystery into a captivating tale of adventure and redemption.