The Onyx Mask. The Vent Chronicles, #2

Lords of gold. Skies of ash. Men of shadow. Stand and face fear itself. With the grand purpose of the Oasis Stone revealed and Zeteph's insidious plans already in motion, Mayve and Srrith find themselves with a singular goal-reach the rainthistle before the masked volcomancer. The plant is nearly extinct, the last of its kind sequestered away in the opulent greenhouses of Citadel Waldheath, and getting aboard the flying island is a daunting task all on its own.
They have no choice; whoever reaches the rainthistle first will control the fate of Ralvera. Raudius and Cindri, far from their homes and short on allies, are also out of options. Cindri refuses to return to the desert without his brother, Ingo, and Raudius seeks to redeem his name. He's found himself fighting alongside Mayve, the very thief he once swore to hunt down. The honorable path is long and arduous, and the Oasis Stone is tantalizingly close, dangling from the belt of his new traveling companion.
Swept into the depths of the Azrak Mountains after his scrap with the glint butchers, Eiklo finds himself following old footsteps. Long forgotten memories, once trapped in his hollow skull, now bubble to the surface as he walks where his living body once did. Traveling through ancient waterways and abandoned tombs, every step takes him farther from Mayve and Srrith, but closer to the fiery slopes of the Ysera Scorch Vent, where he just might find answers on who he used to be.