Time's Up. Mathilda Holiday, #5

Special agents. A hidden bunker. Ancient magic no one was prepared for. Still recovering from her injuries, Mattie refuses to sit still while her sister Tillie and their friend Trevor remain captive. A new ally has uncovered their likely location: the underground headquarters of the Auditors - the secret society that has hunted them from the beginning. Deep inside the bunker, Tillie and Trevor are trapped in sealed cells with no doors, no windows, and no access to their magic.
The organization has finally found a way to neutralize them. Rescue will not be simple. Escape will not be easy. And the power the Auditors are wielding now is older - and more dangerous - than anyone realized. Can Mattie and her allies break into the heart of the organization and end it once and for all? Or will they be crushed beneath the weight of centuries-old magic?The fifth and final installment of the Mathilda Holiday series brings the fight to its breaking point in this fast-paced urban fantasy of secret societies, dangerous magic, and hard-won resistance.