 Not long after the accidental shelling of a lagoon village by the A Battery, 1st Battalion, 14th Field Artillery Regiment, that Alpha Company was protecting (near an American firebase), O'Brien is offered a job at the rear and is airlifted away from the fighting, where he encounters a rear echelon officer, Major Callicles (battalion executive officer), who deals with the investigation into the My Lai Massacre committed by the Charlie Company of the same battalion.The memoir ends with O'Brien being flown home.