Catalina Rodrigues believes she's living her best life, traveling to exotic locations around the world as a scuba dive master, spending every moment possible in her beloved ocean. Bertie Clark is excited for a week-long scuba trip with her husband exploring the underwater wonders of an ocean teeming with life - the Sea of Cortez. But a shocking tragedy on their dive boat sends both women into uncharted territory, questioning what they've always thought to be true and fostering an unlikely friendship. Will either trust the invitation to "come on in, the water's fine" again? Back on land, Catalina does her best to forget what happened on the Calypso. But someone else will never forget and vows to make Catalina pay.