Timothy Zahn is best known for his "Heir to the Empire" trilogy of books that served as the official sequel trilogy to the original three Star Wars movies until Lucasfilm "de-canonized" them. The books are still near-and-dear to the hearts of many fans as well as to many members of the Lucasfilm story group. This is evident in the resurrection in recent "canon" works of the main villain of the books, Grand Admiral Thrawn.
That resurrection is completed with this book, which brings Zahn back to write an official, canon, origin story for this amazing character.
I liked the book, but it's not exactly high literature. I'm pretty sure that anyone who might enjoy it already plans to read it and doesn't need to read my recommendation.