A small Welsh village. An interrupted romance. A rogue frog on the loose threatening their future.

New recruit to the Queen's agents, Dr. Piyali Mukherji is given a simple first assignment. Travel to the small Welsh village of Aberwyn and solve the mystery of a young woman's blue skin lesion. A challenging task, for the alarming infection is unlike anything she's seen before—and it's spreading.

Evan Tredegar, the town's pharmacist and the only man to ever capture her heart, knows more than he's telling. Despite his efforts to push her away, her touch reawakens old desires. As more villagers fall victim to the strange disease, he'll have no choice but to reveal his secrets, even if it means sacrificing his freedom.

Together they must move past broken promises, capture a rogue frog, and stop the infection before it spreads out of control.