“Then there was the fact that the murderer had lit the tilly in Pamela’s room. Jerry heard it being pumped. Jasmine wanted to do the thing properly. She would have needed two hands to force in the knife, so she couldn’t have held a torch. She knew about anatomy. She knew where she wanted the knife to go. She wanted to see what she was doing.”

“But why?” Mark said. He was distressed, agitated. “Why did she have to kill Charlie?”

“It was because of the island, wasn’t it?” Jerry said quietly. “ It was all she had. When she retired she lost all her friends, except us. She hasn’t got any relatives. She doesn’t care about anything else.”

“But she knew Charlie,” Elizabeth interrupted. “ She knew that he was quite likely to change his mind about the island. He was always having weird ideas, but they never usually developed into anything. He wasn’t serious about it.”

“He was serious about this, though,” George said. “It was the lack of motive which disturbed me most. Like you, I thought that Jasmine knew Charlie well enough to realize that he was inconsistent, unreliable. She wouldn’t have murdered him because of a sudden whim, which could have been forgotten on the following day. But he was serious about this. And she knew that he was.”

“But how could she know? She didn’t know any more than the rest of us.”

“I’m afraid that she did. I’m sure that she knew more than a week ago that Charlie was planning to sell the island, that he had been thinking about it for a long time, and that he had already begun negotiations.

“Charlie was short of money. He knew that Jerry was losing enthusiasm for illustrating his stories, and that without the pictures the books were unlikely to sell. He could have sold the cottage at Storr, but he was becoming greedy. He wanted more money than that would have fetched. He had become passionate about the canal-boat project, and you know that he enjoyed being a benefactor. But, more importantly, he had a grand dream for the island. He was becoming bored by the observatory. You see, he wasn’t going to sell Gillibry, just shares in it. He was planning to develop it.

“That, of course, was why he renewed contact with his brothers. He needed their help to turn his scheme into reality. They recognized the financial possibilities and Ernest began to use his contacts to get some dubious plans agreed by the planning department.

“I was blind. I was convinced that Charlie was blackmailing the Todds. I couldn’t think of any other explanation for their reaction to my questions. It was Albert himself who told me that Charlie had instigated the illegal practices which he’d discovered. You can imagine that Jasmine was horrified.

“You see, Charlie’s dream was to turn the island into a miniature Disneyland, with a fun fair, bars, all sorts of attractions. When we were searching the Wendy House we found a ticket for Alton Towers. He had been there while he was in the Midlands. He wanted to turn the island into that sort of amusement park.”