Mrs Bradley did not debate the point, for it seemed to her self-evident. She returned to London next day and found herself involved in her own affairs for almost a week. But on the Friday evening it seemed advisable to give her hard-worked young secretary a break.

‘Laura,’ she said, ‘take the weekend off and report for duty on Tuesday immediately after lunch.’

‘Hot dog!’ said Laura joyously. ‘That means I need not catch a train back until after breakfast. Are you sure you can spare me?’

Mrs Bradley reassured her, and, having seen her off on the six o’clock train, she returned to her Kensington house and continued to cope with certain arrears of work which her holiday in the Cotswolds had made inescapable.

On the Saturday morning she spent four busy hours at her clinic, but on the Saturday afternoon she received by special messenger an invitation to join a friend of hers at the Ideal Home Exhibition. Mrs Bradley telephoned the friend and learned, not altogether to her surprise, that no such invitation had been issued.

She was greatly intrigued and not at all alarmed to discover that she was to have been the victim of a plot. She believed a genuine mistake to have been out of the question; the invitation had been brought by the special messenger with her friend’s compliments, and the friend was named. However, she decided that a few elementary precautions would scarcely be out of place.

She had sent the messenger back with a written acceptance, and then went in her own car to the village of Wandles Parva, where she had her country house. It was all rather fun. She inspected her treasures, had tea in the housekeeper’s room, dined at the village inn off rabbit pie and stewed rhubarb, and took the London road at just after eight.

The night was overcast and promised rain. The car burst a tyre just outside Guildford, and after the slight delay whilst George changed the wheel, she and her man went into the Lion for a drink and a snack.

‘Have we been followed, George?’ Mrs Bradley enquired as they sat at a small table. George had been provided with a pint, and his employer (out of deference to the rhubarb, of whose unsweetened effects she was dubious), had chosen a loathsome but efficacious mixture of port and brandy. The chauffeur set down his tankard.

‘I am inclined to think so, madam. I could take the stretch into Esher a bit faster if you should wish it.’

‘Do so, George. We might as well try their mettle. Swallow, George, and let us go out to the car under the cover afforded by this large and animated party which I see is preparing to leave.’