Red Agent: The Human Order (Red Agent: The Human Order #7)

Fire and Ice Britney and her team race to Iceland to stop Ember, an evil Highborn who is planning to cause a volcanic eruption. If they fail, most of Europe will be blanketed in ash and dust, leading to massive loss of life and altering the fabric of European society for a generation. But to get to Ember, Britney, Avril and Silk must navigate rivers of lava, sulfurous caverns, and monsters borne of fire.