Apart from church on Sundays, when he carried her missal, they were never seen together. She went to old-time dancing Wednesdays and Fridays, and at weekends, apart from church. Harkness sailed his radio-controlled model of the Cutty Sark on the Round Pond in Kensington Gardens. Even then he wore a hard-collared shirt and a waistcoat.

‘What was the reaction?’ asked Harkness.

‘What I expected,’ said Wilson. ‘The instruction is absolute discretion.’

‘I thought that went with the job.’

‘No arrest or trial.’

‘Oh,’ said Harkness heavily.

‘It makes good political sense,’

‘What about moral sense?’

‘Naire-Hamilton’s morals are political.’

Harkness appeared about to challenge the assertion, but swallowed it back. ‘We’ve still got a lot of phoney messages to go. Shall I withdraw them?’

‘No,’ said Wilson at once. ‘People had to be involved at the Foreign Office: if we stop, they’ll know we’ve got a lead. They might even identify it, by a process of elimination. I’m not risking another Philby situation, a protector back here at base.’

‘All the Rome personnel files will be processed by tomorrow,’ promised Harkness.

‘We might get a lead,’ said Wilson doubtfully. ‘What about the embassy itself?’

‘Completely isolated from anything sensitive.’

Wilson leaned back reflectively in his chair; again the leather patches squeaked rudely. ‘We’ve got an advantage there,’ he said.

‘What?’

‘The Summit,’ said the director. ‘We can move a squad into the embassy, as supposed security for the meeting.’

‘Any specific instructions?’

‘Not yet. It’s isolated, as you say. So there’s no danger any more. The only risk is that our man might get nervous and run; a defection could create the sort of embarrassment Naire-Hamilton is frightened of.’ Wilson swivelled his chair towards the window. Outside, a stacked jet, waiting for Heathrow landing permission, appeared to hover over the Houses of Parliament. ‘What about Hotovy?’ said the director suddenly.