The Doomsday Key

I liked this book written by James Rollins. When a famous geneticist, a Vatican archaeologist, and a Senator’s son are all found dead, the only similarity is the pagan cross seared into their flesh. As Commander Pierce and his team struggle to trace the connection, a trio of high-tech assassins aims to end their investigation. Forced to run, Pierce enlists the help of two women from his past – one of whom he’ll have to sacrifice in order to save the world.

This is the sixth book in the Sigma Force series.