Second book in the Underground Guardians series.

The battle with the Arions continues.

The genetically enhanced Black Knights battle to save the world from the Arions. But to harness their special powers, they need help from the outside, someone who understands how to seize the power and complexity of the mind. Marcella Alexander, a woman considered myth by most, is named the Witch Doctor for her unique healing powers. But Marcella has gone into hiding.

Diego, doctor of the Knights, is picked to lead the search to find Marcella and bring her back to join them in the battle. But upon locating her, Diego makes a shocking discovery…she is his mate.

As they travel through Mexico, fighting their way back to the Black Knights, Diego and Marcella discover that the passion they share and their entwined soul empower them, allowing them to face any challenge their future may hold.