'Just War', written by Lance Parkin, features the Seventh Doctor, Bernice, Roz, and Chris.
Back Cover Blurb
'Tomorrow belongs to us, not you. If you were really from the future, Miss Summerfield, you would be a Nazi.'
March 1941: Britain's darkest hour. The Nazis occupy British soil and British citizens are being deported to European concentration camps. Six thousand people a month are dying in air raids on London. The United States show no sign of entering the war.
According to the Doctor, this ins't a parallel universe, it isn't an alternate timline, and everything is running according to schedule. But now something, somewhere, has gone wrong. The Nazis are building a secret weapon, one that will have a decisive effect on the outcome of the war. Chris thinks it's a UFO, while Roz believes that the Luftwaffe have developed the largest bomber ever built. Only Benny may have seen the mysterious craft - but she's disappeared off the face of the Earth.