Dani, Rocco and Sarah, patients at Dr. James Shepherd's Nightingale Children's Hospital, follow a strange noise to an elevator which takes them to a place they could never imagine, a place full of wonder...and Darkness.
Dani, Rocco and Sarah encounter the powerful force terrorizing Nightingale before being yanked back to the real world. Will they play it safe...or try to become heroes?
When The Darkness attacks, Nails saves the day by calling on a surprising new skill. Dr. Shepherd attempts to stop Dani, Rocco and Sarah from their mission.
Dani meets a mysterious girl who sends her and Rocco on a quest to retrieve a powerful item from the depths of a "Lake with No Bottom." Sarah finds herself in a confrontation with Dr. Shepherd. But is he a friend...or a dangerous foe?
Dr. Shepherd finally comes clean about his long connection to Nightingale. He attempts to stop Dani, Sarah and Rocco from returning, but they find new allies in Dani's Uncle Lawrence...and a young adventurer named George.
WIth George by their side, Dani, Rocco and Sarah seek clues from an ancient Makri known as The Seer. But with the doors left open, something escapes from Nightingale.
A new threat challenges Dr. Shepherd and his entire hospital. Dani, Sarah and Rocco begin their journey to save Nightingale, but the minions of the Darkness put them - and Nails - in immediate peril.
Dani reels from a terrible loss and receives troubling news about her own condition. Dani, Rocco and Sarah's parents look for answers from Dr. Shepherd, but are instead confronted by his adversaries.
With Dani out of commission, Sarah and Rocco must continue the quest on their own. As the Darkness drives them apart, a new villain emerges with an even deeper history in Nightingale.