Trackers

Detective Richard Zimmerich of Fort Myers PD is faced with three deaths and one case of alleged child abuse by her nanny at the SWFI airport. All four cases have only one thing in common. The victims wore a fitness tracker with the brand name, Joggit.
Meanwhile, Lt. Mark Skitter is on board a military Medivac copter which is carrying a comatose Lt. Stan Crammer. They are headed. to a contractor's research facility on an island south west of Captiva islands. Lt. Crammer has been testing the contractor BioNev's new technology, which directly interfaces human brains with computers, through a wearable device resembling a fitness tracker.
This technology is being developed for DARPA's BTO Division under its NESD program for its HTV - 3 project. Now, something has gone wrong and BioNev's team needs to find a cure for Lt. Crammer.
Detective Zimmerich finds that the comatose child Anne has woken up and claims to be Lt. Crammer. He contacts Lt. Skitter with the information that Anne gives. Lt. Skitter flies Zimmerich along with the child, her nanny, and the child's mother to the island.
Things take a turn when Skitter and Zimmerich discover that the core technology behind BioNev's breakthrough is a biological computer built out of living cells. BioNev's principals have shared the technology with a sister advertising firm that plans to sell 'active' advertising through the technology.

Using this technology, sellers can force wearers of the interface devices disguised and sold as fitness trackers to buy specific products, and even force their decisions.