After an explosion in the middle of a city, former lovers, Isobel and Diego, find themselves rekindling their relationship. But the explosion was caused by a mysterious artefact, now under military control, and containing details of new technology that may just save the planet. In a few years time, the world will be overcome by a massive pandemic. But the artefact contains both the plans to send someone back to prevent the problem from occurring and pointing at Isobel and Diego as both the people to go back and the way to prevent the devastation if they had never split up in the first place. All Isobel has to do is convince the young version of her former lover to be patient and stay with the younger version of herself, even when she desperately wants him for her own.

This is really a story of two halves. The first half of the story introduces all the characters, sets up the world and pushes the plot through. The second half is mainly around Isobel in the past and how she interacts with a younger Diego. It is almost like it cannot decide what kind of book it is going to be, an apocalyptic sci-fi thriller or a tragic romance and so it attempts to do both. The characters are well written in both sections and their desperation as they seek to survive the disaster overcoming them is heartfelt. The survival elements come across harshly and there is a real struggle that keep the pages turning, but when it switches to the time in the past, the struggle is far more about trying to force two people together and giving someone the knowledge and understanding to go through with it, in the hopes it can save everyone. If it had stuck to one type of storytelling, this would be a book I would suggest to read, but unless you like both styles, you are likely to be put off by one half of the book.

Overall, it’s a well-written story, let down only by the unexpected change of pace and tone half way through.