"Why don't you just call me Doctor?"
"Zat ist not a name. I vant your full name."
"Oh very well. Dr. John Smith."
"Goot. Now ve are gettink somevhere."
"I realise our presence behind you lines must seem rather strange. And suspicious?"
"No? Oh, I was rather expecting you to accuse us of being spies. Everyone else does."
"I know you're not spies. Ze vun sink you definitely can't be is spies. After all, if ze British had sent spies to infiltrate our lines, zey vouldn't send two officers in British Army uniforms in a British Red Cross ambulance vith sree people in civilian clothes, all speaking English. Zey'd send people in German uniforms in a German vehicle, all speaking German vizout an accent and all claiming to be German. Zat's how spyink vurks, you see."
"It could be a double bluff?"
"No, zat is just stupid."
"Well, if you'll just put down your gun, I'll prove that I'm from the future by dismantling it."