I must admit this one caught me totally by surprise, and would definitely qualify as the best Gerritsen I've read yet. Emma Watson (not the actress) is sent to the International Space Station as a replacement for an astronaut who had to return to earth for his wife's funeral. When she arrives, she soon discovers one of the experiments on the vessel has gone horribly wrong: an alien virus is loose and is slowly infecting and killing all on board. It becomes a race as she and her husband (who is still on earth) try to find a way to save her from a certain gruesome end. This is truly a page turner, and keeps you guessing (and gasping) to the very end. I highly recommend this one for thrill-seekers in books.