The Art of Time

Nola Grace is a Time Key. She has the ability to enter other worlds through the paintings created by the Archivists. When she is fifteen, the hiding place her mother found for her is discovered by those who want to control the multiple worlds behind the paintings.
Inadvertently pulling Danny Morgan through the paintings with her, a furious chase begins as those who want to exploit her power, and those seeking to protect her, wage a developing conflict.
Nola and Danny quickly learn that they can only trust each other, and that they must look to save themselves.