The Raiders of Herion (Stolenworld) by K.A Krisko

It’s been two years since the Battle of Hyolon, and Duri, Anseri, and Torvin are struggling to make a living as traders. They’ve got their sights set on the Closed City of Herion and a possible windfall. But Herion has remained untouched for a good reason: it’s haunted, dangerous, and deadly. Some of what they need to know about the city resides with one of their arch-enemies. They may have a plan to secure his cooperation and get the information they need – or they may end up trapped in Herion forever.