After returning home to the Florida Keys, Jesse moves on to Fort Myers, his hometown on the Southwest Florida coast. There is much work to be done, and Jesse is no stranger to hard work.

On a kayak outing with friends, Jesse's daughter finds and rescues a manatee suffering from respiratory problems. The red tide has returned, and fish are dying by the thousands, along with dolphins, manatees, and sea birds.

The algal bloom is a naturally occurring phenomenon, but this time it's much worse. Theories abound; it's something left over from the previous spring's coronavirus outbreak, it's caused by pollution, someone is intentionally creating a super-algae....

But there's something far more sinister at work, and it's up to Jesse to find out what it is and put a stop to it.