This is the third book in the Ulysses Moore series.
Now that the children are home, they learn that Ulysses Moore isn’t the only one who has one of the keys to the newly discovered doors. Now they must follow him back in time to try to get the key before Oblivia does.
Rating: 8.5/10 – I enjoyed this book a little more then the rest of the series. A lot of the mysteries from the previous books came together in this story.