Tanzanite, a rare blue gem born in fire and revealed by lightning, is found only in the Merelani Hills of Tanzania. But now the death of a gem smuggler points to another possibility. A South American mine owned by Tabitha Metals may hold the find of a century. But why is it kept hidden from the world? Geologist Brian Graham can draw only one conclusion: the mine's untraceable wealth is used to fund terrorism. And he must reveal the truth. Brian...