The Doomsday Key is a down-and-dirty thriller. Part religious mystery, part end-of-mankind warning, it utilizes an uber-secret military agency and modern issues to attract readers across multiple genres. It is similar to a Dan Brown/Tom Clancy mash-up, and it works very well.Like most modern thrillers, The Doomsday Key isn't award-winning literature. However, this does not stop the reader from frantically turning pages, anxious to find out what happens next. At the same time, Mr. Rollins creates a forum by which he can present the very real possibility of food shortages due to a burgeoning global population and the power plays that have already started as a result of such shortages. He presents these modern issues in a way that is thrilling, fun, and yet fairly realistic.What adds to the story the most is the fact that Mr. Rollins takes the time to delineate the truth and the fiction in his novel. The fact that there really was a Domesday book with mysterious underpinnings and a Doomsday vault heightens the tension. More importantly, Mr. Rollins highlights the religious mysteries, what is real and what is speculation. Mr. Rollins' research, and his sharing of this research makes the entire story that much more credible and subsequently more thrilling.As the sixth book of the Sigma Force series, I am definitely interested in reading more of the series, although for those who have not yet started the series will be happy to know that reading the previous novels is not necessary to enjoy this one. The Doomsday Key is fun, escapist literature that will be sure to please thriller lovers everywhere.