The show centers on a group of young FBI recruits battling their way through training at the Quantico base in Virginia, one of whom will turn out to be a sleeper terrorist responsible for the most devastating terrorist attack on U.S. soil since 9/11.
Sorry, no info about the next episode of Quantico is available yet.
However, our last information about it is this:
cinemablend.com, July 2017: "Though Quantico is returning for at least one more year, it will do so without some of its cast members. Two actors have announced they will be leaving the ABC thriller drama series ahead of Season 3. Pearl Thusi and Yasmine Al Massri have both announced their departures."