‘Talk and tea is his speciality,’ said Giles. ‘He has about five cups of tea a day. But he works splendidly when we are looking.’

‘Come out and see the garden,’ said Gwenda.

They showed her the house and the garden, and Miss Marple made the proper comments. If Gwenda had feared her shrewd observation of something amiss, then Gwenda was wrong. For Miss Marple showed no cognizance of anything unusual.

Yet, strangely enough, it was Gwenda who acted in an unpredictable manner. She interrupted Miss Marple in the midst of a little anecdote about a child and a seashell to say breathlessly to Giles:

‘I don’t care-I’m going to tell her…’ 

Miss Marple turned her head attentively. Giles started to speak, then stopped. Finally he said, ‘Well, it’s your funeral, Gwenda.’

And so Gwenda poured it all out. Their call on Dr Kennedy and his subsequent call on them and what he had told them.

‘That was what you meant in London, wasn’t it?’ Gwenda asked breathlessly. ‘You thought, then, that-that my father might be involved?’

Miss Marple said gently, ‘It occurred to me as a possibility-yes. “Helen” might very well be a young stepmother-and in a case of-er-strangling, it is so often a husband who is involved.’

Miss Marple spoke as one who observes natural phenomena without surprise or emotion.

‘I do see why you urged us to leave it alone,’ said Gwenda. ‘Oh, and I wish now we had. But one can’t go back.’

‘No,’ said Miss Marple, ‘one can’t go back.’

‘And now you’d better listen to Giles. He’s been making objections and suggestions.’

‘All I say is,’ said Giles, ‘that it doesn’t fit.’

And lucidly, clearly, he went over the points as he had previously outlined them to Gwenda.

Then he particularized his final theory.

‘If you’ll only convince Gwenda that that’s the only way it could have been.’ 

Miss Marple’s eyes went from him to Gwenda and back again.

‘It is a perfectly reasonable hypothesis,’ she said. ‘But there is always, as you yourself pointed out, Mr Reed, the possibility of X.’

‘X!’ said Gwenda.

‘The unknown factor,’ said Miss Marple. ‘Someone, shall we say, who hasn’t appeared yet-but whose presence, behind the obvious facts, can be deduced.’

‘We’re going to the Sanatorium in Norfolk where my father died,’ said Gwenda. ‘Perhaps we’ll find out something there.’