I did not like the ending, but recommend the story. We thoroughly enjoyed this book as my wife read it out loud to both me and my son. As I said about the first Harry Potter book, anyone from 9 to 90 would enjoy it. It does, however, capture the excitement of the current quest for a better theory of physics. They are the two most successful theories ever invented by the human mind.
Experiments verify their predictions with more accuracy than has ever been achieved in the past.
Unfortunately, they are incompatible and their predictive powers fall apart in some situations. This book describes String Theory, which looks like it could resolve these problems and many others. However, at this point the physics and mathematics are so complex, so advanced, that they cannot even be worked out in detail. This book explains why there is so much excitement among scientists for a theory that cannot yet be tested. The beauty of string theory is that both the theories of gravity and the quantum naturally emerge from it.