Bannerman turned the sheet around. There was a drawing on it. A line drawing in pencil of extraordinary perspective and depth. In the foreground the figure of a thin man in a long coat was coming through a doorway. There were foreground scribblings on the wall that seemed to form a pattern. Wallpaper perhaps. Through the door, and behind the central figure, stood a large stone or marble fireplace. Part of an armchair was visible, a framed picture on the wall with the outline of a head. The drawing was vividly evocative, and yet distorted as if seen through a fisheye lens. Or a disturbed mind. There was something almost sinister about the figure in the foreground. It seemed to be stepping right out of the page. But most striking was the man’s lack of facial detail. Tania had drawn only the outline of the head and ears. Everything else was observed in such detail that you would not have thought a child capable of retaining it, never mind reproducing it. But there was no face.

Bannerman was fascinated, confused. ‘I don’t understand,’ he said.

Du Maurier lit a third cigarette from his second one and blew a jet of smoke at the Anglepoise. ‘The picture on the wall in the background represents a head-and-shoulders portrait, a Rubens copy that hangs above a marble fireplace in Monsieur Gryffe’s house in the Rue de Pavie. If you stand in the cloakroom in the hall and look through the open door into the back room you can see almost exactly what the child has represented in the drawing, including part of the armchair. The scribblings on the foreground wall seem to represent the patterned paper in the hall. The drawing is uncannily accurate. I have just returned from a visit to the house to make the comparison myself.’

Bannerman thought about it for a few moments. ‘And the face of the man?’

Du Maurier shook his head.‘If our meeting had lasted just a few minutes longer the child might have had time to complete the face. But she was interrupted before she had finished and nothing would make her continue. As you can see, almost everything else is so detailed. Buttons, pockets, hands. The carer, Sally, told us that the child often begins her drawings with an outline and then works inwards.’

Bannerman looked at the drawing again. It was hard to believe that it had come from the hand of an eleven-year-old. He looked up to find du Maurier watching him. ‘And who is the figure in the foreground?’

The Inspector sighed. ‘The man is too slight to have been Monsieur Gryffe. And if it had been her father, then surely the outline of the head would have indicated the beard.’

‘So there was a third party.’

‘Possibly.’

‘Who didn’t know the child was there?’

Du Maurier shrugged wearily. ‘Perhaps. Though it’s difficult to imagine how.’