On this edition of Conversations, Sarwat Chadda talks with host Dan Skinner about “City of the Plague God.” Chadda is a first-generation Muslim immigrant who swapped a career in engineering for a new one as a writer. His previous novels include “Devil’s Kiss,” the award-winning Indian mythology-inspired “Ash Mistry” series, and the epic high-fantasy “Shadow Magic” trilogy (using the name Joshua Khan).