Westenhanger continued his explanation.
“Now look at where the bell has been placed. That’s the really important point. The thief might have been a right-handed man and used his right hand to take the Talisman; then, after he had got it, he might have closed the door he had used and opened the left-hand one. But the bell gives him away.”
Douglas examined the case closely.
“The bell’s slightly to the right of its old position. Is that what you mean?”
Westenhanger nodded.
“That’s it. A right-handed man goes in at the right-hand door, just as you both did. Then he crooks his elbow towards his chest to get his hand over to the Talisman. That brings his hand to the centre of the case. It’s a narrow case, you notice. Not much room to manœuvre in it.”
“I see,” said Eileen. “He’d pick up the bell; and he’d have to put it down again—clear of the Talisman—in order to pick up the jewel. If he put it down on the right-hand side of the case, it would be in the way of his arm in getting out again, so he’d set it down beyond the Talisman, towards the left of the case. Then he’d pick up the Talisman and take his hand and arm out of the case. Is that it?”
“Yes,” confirmed Westenhanger. “That’s what a right-handed man would do. And since the bell’s been set down towards the right hand of the cabinet, it’s obvious that there’s been a left-hander at work, isn’t it?”
“That seems right,” Eileen admitted. “It’s very clever of you to have noticed it.”
“You noticed it yourself. It just happened that I was lucky enough to spot the thing almost at once.”