“Chiasson” is a darkly comedic mystery series by Donna Grant, following the relentlessly grumpy and stubbornly independent Gus Chiasson as he investigates disappearances in the remote fishing community of Shippanois, Louisiana. The series blends elements of noir and Southern Gothic with a sharp, cynical voice and a focus on small-town secrets and eccentric characters. It’s distinctive for its unique blend of humor and suspense, and Gus’s particular brand of reluctant heroism.