'Little spark . . . you are changed.' Antissa has come under Ratheine attack; not from the walls, but from below - her ancient pipes. The flooded Hub threatens collapse of the Deep under the fortress, while the scheming Sanhedrin council creeps ever closer to removing Rusper Symphin as Viceroy; the engineer whose protection of the refugees from Naemia amounts to treason. Tool to a nation on the brink, a Naemian boy enters the desert. Armed with the Disc's arcane "Sight", Florian Flint now takes his place on a secret task-force contingent led by the High Commander Plamen. Its urgent purpose - in nine days - to locate the hidden river system by which the Rath accessed the pipeworks: the key strategic advantage in Vorth's return to open war. The Disc itself has other thoughts. Cover art by Natasa Ilincic Additional images, inc. maps:  https://photos.app.goo.gl/CdNo1rEjvR7RdVzD7 Tools of War is the 2nd volume of Deep Mettle, a 2-volume fantasy fiction. Pipes and Fusils, the 1st volume, is also available to read on Royal Road. Available from AMAZON in paperback, hardcover & e-book formats. Find out more at https://www.voidstep.com/