4 stars. Dark Angel is a rocketing thrill ride that never lets up. Lettie Davenport goes undercover with an NSA computer geek to infiltrate a dangerous group of hackers…or is there more to their assignment than they are being told? As the body count rises, Lettie discovers the hackers may not be the enemy she was led to believe as she is dragged into a plot twist ripped from the headlines. Sandford masterfully keeps the story tight and the characters moving at a breakneck pace that will have readers on the edge of their seats and losing sleep to finish the book. Four very well deserved stars for this one. I was given a copy-this is my own opinion.