This book was recommended by our school librarian, and I gave it a rating of four out of five. Liam, Maddy, Sal, and an artificial intelligence named Bob are in charge of keeping the correct version of history intact. They are able to travel into the past or the future to fix any events in history. In this book, Liam is sent into the future to save the life of a boy named Chan, a key person in the creation of time travel. However, in the process of saving Chan, there is a huge explosion that sends about a dozen people back in time to 65,000,000 B.C. The group needs to figure out a way to send a message to Maddy and Sal to let them know where/when they have been sent in history without leaving any evidence that might change the course of history. To make matters worse, the group must survive attacks by intelligent reptiles that work and communicate with each other and have the ability to learn. Some members of the group don't make it.
The beginning of the book was a little confusing as the setting jumped to several times in history. However, it quickly settled down to two settings and was easier to follow. This book requires some thought to follow the plot and keep things in order. The present-day characters are trying to figure out ways to find Liam and Beck, a female version of Bob, and other characters show as history seems to be altered. I guess this book is actually the second one in the series; the first book is called Time Riders.
