The Caribbean. Something is happening in the coastal waters off Cuba. Toxic mercury plumes are killing wildlife and fishermen are mysteriously vanishing. But what is behind it? When NUMA launches an investigation, they find mysterious holes in the seabed. Someone or something is drilling into the crust - and they don't care what or whom they harm. And the Caribbean is a really big place to hide what you're up to. But if anyone can find out who's behind this, what they want and put a stop to it, it's the man in charge of NUMA - Dirk Pitt.