A retrieving tool for retrieving an annular hollow baffle member in a wellbore. The baffle member has an interior bore and radially outwardly-biased collet finger protuberances on an exterior thereof matingly engaging a correspondingly-dimensioned annular recess within a landing sub of a well casing of the wellbore. The retrieving tool has a tubular body and a plurality of radially-outwardly-extendable dogs thereon. The tubular body and the dogs are sized that, when the dogs are retracted, the retrieving tool is movable through the interior bore of the baffle member to a position below a lowermost thereof, and when the dogs are extended after the retrieving tool moves to said position, the dogs radially engageable with the landing sub and axially engageable with the lowermost of baffle member for pulling the baffle member uphole and disengaging it from the landing sub for retrieving the entirety of the baffle member.