Fantastic! I love the Sigma books because Rollins weaves interesting scientific & historical facts into a kick-ass action-adventure plot, but he also digs down into characters and shows us the more tender side of the 'scientists with guns'. We see the development of Gray and Seichan, as well as the brilliant partnership of Kat & Monk back on deck. Rollins' female characters can all shoot and fight with the best of the guys, which I enjoy. The new characters of Tucker & his war dog Kane were excellent and original, adding an element that compliments Rollins past career as a vet. The story line of genetics and bio-tech was interesting and a great device to hang the plot on. I read this late into the night to finish in one sitting. Highly recommended!