The Book of Doors by Gareth Brown
Rating = ****

An early leader for my book of the year. It's an inventive story involving books that 
bestow various powers on whoever has possession. The book of doors allows you to time 
and place travel simply by walking holding the book, thinking of where or where and 
when you want to go, and walking through any door.Our heroine Cassie comes into 
possession of the Book of Doors, and upon realizing its power, finds herself pursued 
across time and space by dark forces that would possess the book for evil. So time 
travel set in the modern-day world with good and evil, all very well executed.