Red tide a toxic algae bloom infiltrates a small Florida town leaving its economy in ruin, and forcing the local fishermen and divers to do whatever they can to make a living. Alex Nikoladis returns home from prison to find that his older brother is wrapped up in a world of drugs, lies, and death. Now Alex's only hope for redemption from his rebellious past is to rescue his brother and return to the family trade of sponge diving, that is, without drowning in the red tide.