Our Peregrines journey to many different places in search of the last piece of armor while Dekker reforges the swords and recoats the Armor of God in preparation for the final battle.

The inhabitants of Reader's Island need a way to unwind from the recent demon battle and plan a night of revelry on the island, and with the discovery of time-travel possible for most anyone, can Jason finally be with Memnah and bring her to the island?

Many things take place between travels as our Peregrines once again split up to find the last piece of armor. Travel to places such as Craco, Italy to a long abandoned city still standing today. An old church in London, England now serving as a botanical respite for London's citizens. The underground city of Derinkuyu in Cappadocia, Turkey and the Mesa Verde Cliff Palace in Colorado, USA hold many secrets. Last but not least follow Seth's group as they explore the city of Al Khazneh in Petra, Jordan, a beautiful city carved into the mountains.

Can the twelve defeat the beasts to save mankind? Read this last book to find out.