I read the Percy Jackson series and I did not hesitate when this book came out (I usually do not buy hardcovers).
The formula of the book to some extent is very similar to the Jackson series, minus the learning disabilities, a character that the parent is missing, a mystical heritage, gods, demons and special friends. The big difference the heroe is actually two kids, a pair of brother and sister apart since they were kids that by the actions of their father end up learning more about themselves and the need to become a family.
This is the first book in a trilogy and it has a beginning, middle and an end to the story. We are not left with a cliffhanger but with a resolution against the big bad.
In a manner of speaking a formula very similar to the Harry Potter books.
My four stars is for the way the story is told from the point of view of one of the kids. Every chapter or every two chapters the story is narrated by one of the Kane siblings depending on who is taking action. This at times was frustrating because the character of Sadie Kane does not come at first as your popular nice hero, but an obnoxious, spoiled little girl that does not make you feel sorry for her; making her chapters harder to read and feel sympathy for the so called hero.
Otherwise is a great read and with the price amazon is offering a PLUS.
Get your book and enjoy it for what it is.... A very light adventure to entertain you