The flash is an american television series developed by greg berlanti andrew kreisberg and geoff johns airing on the cw it is based on the dc comics character barry allen flash a costumed superhero crime fighter with the power to move at superhuman speeds it is a spin off from arrow existing in the same fictional universe the series follows allen portrayed by grant gustin a crime scene investigator who gains super human speed which he uses to fight criminals including others who have also gaine