The Royals are posted to West Germany and 6 Platoon have been given a new CO. Meanwhile, Colby schemes to get rid of the troublesome Stevens, who reveals one of the (many) reasons for his rage.
The strains in Box's marriage lead him to a blunder during tank exercises. His wife is lonely, homesick and harbouring a secret. And Gadd's stag party (he's getting married in the morning) turns rancourous.
Twiss and Gilbey are both thinking about promotion. Bilinski wants to marry Helga, but she's an escapee from communist East Germany, and Army Intelligence thinks she may be a spy.
Adams's father visits from England. Tensions are still high between them, but a visit to the museum of Belsen concentration camp has a surprising effect. Stevens, permanently angry and deeply unpopular, receives some devastating news.
Pickering causes a serious incident on the heavily defended border between East and West Germany, forcing 6 Platoon to weigh up the conflicting demands of humanity, group loyalty, and military discipline.
6 Platoon are back on active duty in Northern Ireland. During a nighttime surveillance operation, they're ambushed and Twiss goes missing, presumed captured. Enquiries among locals are met with bitter and mutual hostility.