The letter was bitter and unforgiving and always caused him pain whenever he thought about it. Yet, and this always touched him to the quick, the parcel in which she had sent it included a hot-water bottle for Eva. Hot-water bottles were hard to obtain in Czechoslovakia and Eva had been fond of them. He could not quite understand why he acted as he did but, having got the letter out of the clutches of the censors, he destroyed it. But not the hot-water bottle.

‘I still believe in its aims,’ he replied, with a stab at the fervour which had once propelled his actions. ‘These are good and true. I’m a Party man, through and through. But that doesn’t mean that the Party should ignore the need for change.’

‘Spoken like a diplomat.’

The bargain had been forced on him on his sixteenth birthday, made as he faced the unknown man in a beige mackintosh and a pork-pie hat. Five minutes previously, this stranger had knocked on the door of his parents’ rooms in the Malá Strana and asked to speak to Petr Kobes.

‘I am he. Your name?’

‘It’s of no importance.’

Without asking permission, the man placed his briefcase on the table. The briefcase was made of good leather and looked new and Petr eyed it curiously. Not many of those around. The nameless visitor opened it and passed papers over to Petr. ‘You need to read and sign these.’

‘Why? What’s in them?’

The focused gaze from under the pork-pie hat told Petr that it was unwise to ask questions.

‘You will be working for us,’ was the reply. ‘We have been observing you and you are considered the right material. Signing will give your formal permission. We like to have matters documented.’

‘But—’

‘If I were you, no “but”s.’ The stranger’s gaze moved around the room that doubled up as kitchen and living space, taking in the empty shelving, the patched lino flooring, the two-ring gas hob, the tin kettle and, eventually, came to rest on the door behind which his ailing mother was sleeping. ‘You will be needing to get hold of your mother’s medicine in the future.’

Petr still didn’t reply.

‘I don’t expect you would enjoy military service much either,’ the stranger added.

Everyone in Czechoslovakia knew that those sorts of statements contained a threat that could last for a lifetime and it was mad to ignore them.

After he had signed, the man produced a package from the briefcase. ‘Chocolates for your mother.’

Petr could not remember when he had last seen a box of chocolates, if ever, and they riveted him. This, of course, was their point.

The man nudged the chocolates into the centre of the table where they rested, incongruous in gaudy tinsel ribbon. ‘We will continue to observe you,’ he said.