A girl with a clockwork heart makes every second count.

When Penny Farthing nearly died, the brilliant surgeon Calvin Warwick managed to implant a brass "Ticker," transforming her into "the first of the Augmented!" But soon it was discovered that Warwick kidnapped and killed dozens of people striving to perfect another Ticker for Penny.

The last day of Warwick's trial, the Farthing factory is bombed, Warwick disappears, and Penny and her brother, Nic, receive a ransom demand for all of their Augmentation notes if they want to see their parents again. Who is trying to stop their work? Or to control it? Or is the motive more sinister?

Determined to solve the mystery and reunite their family, the Farthings recruit their closest friends: fiery baker Violet Nesselrode and gentleman-about-town Sebastian Stirling. Unexpectedly leading the charge is Marcus Kingsley, the young army general who has his own reasons for wanting to lift the veil between this world and the next. Wagers are placed, friends are lost, romance stages an ambush, and time is running out for the girl with the clockwork heart.