This was an excellent, fast-paced adventure and fantasy story. The pace was so non-stop that I found myself wishing that a break in the action about 3/4ths through was the end (which is also when different characters got their own chapters and the story didn't flow quite as well). I enjoyed the siblings' relationship - their funny bickering and fierce love for each other. The explanation of the time travel was a bit befuddling - easier to just accept how it is and move on (which the author practically advises). This was my first audiobook narrated by Jim Dale, and I understand why he's so popular. His various character voices were great.A longish book, it'd be a good suggestion for those who liked Fablehaven, Percy Jackson, and Inkheart.