He blew a piercing blast on a tin whistle. William rang the minute station bell and pressed a button. The toy train lit up and moved out of the station.

‘Now I take over till we reach Crewe,’ said Robin. He and William changed places and the train increased its speed. William answered a toy telephone.

‘Midnight express. Urgent call. Yes?’ he panted and blew. ‘Gaston Sears speaks,’ he gasped. ‘Stop the train at Crewe. He’s hurt and he’s due at the theatre at seven.’

‘Coming into Crewe. Clear the line.’

William produced a white van with a red cross and placed it on a side line. ‘Ready for Mr Sears,’ he said.

‘Where is Sears?’

William emptied out a box of toy soldiers: Army, Navy, Highlanders and Crusaders. He cried out triumphantly and displayed a battered Crusader with an enormous sword and full mask and black cloak. ‘Look! Perfect,’ he cried. ‘In every detail.’

‘Hooray! Put him in the van.’

The game proceeded with the preposterous illogic of a child’s dream and several changes of plot, but the train arrived conveniently at Euston Station, ‘Gaston Sears’ was pushed on to a battered car and, remarking that he’d got his ‘second wind’, was sent to the Dolphin Theatre. End of game.

‘That was fun,’ said Robin, ‘wasn’t it?’

‘Yes,’ his father agreed. ‘Why did you have Gaston Sears in it?’

‘Why not?’ Robin replied with a shrug. He walked away. He was no longer interested.

‘Because he was breathless and tried not to be?’ William suggested vaguely. ‘It’s asthma but he pretends it isn’t now he’s an actor again.’

‘I see,’ Peregrine lied. ‘Show it to me. The toy Sears.’

William took the battered little figure out of the car. A shrewd whack in some past contest had disposed of the cross on its cloak. The sword, bent but intact, was raised above its shrouded head in gloved hands. It was completely black and in its disreputable way quite baleful. ‘Thank you,’ said Peregrine. He put it in his pocket.

‘Have you finished with the train?’ asked Emily.

‘We might want it later,’ Robin said quickly.

‘I don’t think you will. It’s The Duke on telly in a quarter of an hour and then teatime.’

‘Oh, Mummy!’

The train was carefully put away and the toy soldiers swept into their box pell-mell. All except the ‘Mr Sears’ which was still in Peregrine’s pocket when he looked at his watch and prepared to leave.

‘I must be off,’ he said. ‘I don’t know when I’ll get home, my love. Cip says he’ll come down with me and walk back, so I’ll leave you to take William home. OK? Good evening, William. Come again soon, won’t you? We’ve enjoyed having you here.’

‘Thank you, sir,’ said William, shaking hands. ‘It’s been a lovely day. The nicest day I’ve ever had.’

‘Good. Cip! Ready?’