Dolly was playing his part well, smiling as if he was amused by the antics of a monkey.

The others were coming back, the deputy-commandant with an angry light in his dull eye.

'Speaking to the prisoners is forbidden,' he shouted.
I looked blankly at him till the lieutenant translated.
'What kind of fellow is he ?' said Dolly in English to the doctor.

'He spoils my game and then jabbers High-Dutch at me.' Officially I knew English, and that speech of Dolly's gave me my cue.
I pretended to be very angry with the very damned Englishman, and went out of the room close by the deputy-commandant, grumbling like a sick jackal.

After that I had to act a bit.