Sussex was the first country secured by the Roundheads because of its iron foundries. Here in the Weald, the Smith tribe are working for Parliament, making cannons and weaponry. They have prospered under Cromwell's rule, and have no interest in old gypsy charms. It is here where Luka and Emilia must find the fifth charm, a finely-wrought lightning bolt. Amidst the smoke and noise of the Horsmonden foundry, the gypsy children run into old friends...and old enemies.