I went into Twice Upon a Time expecting a fun time travel adventure, and as it turns out that's not quite what this is. The twins do however have really interesting time-related powers and use them to investigate a more-than-decade-old crime. 

It's a really great fantasy mystery story and I love the sibling bond between the girls. It took a couple of chapters to fully hook me on the story, but once it got going it was really compelling and I didn't want to put the book down. Like the main character I love limericks and it was so much fun to read so many of them within the novel. The resolution to the mystery felt a bit too unlikely as an adult reader, but I imagine probably won't bother children - who are after all the audience this book is aimed at. 

I had a great time with this book and highly recommend it.