‘A most fortunate escape,’ said Mr Falls gravely. ‘Well now, gentlemen—I have almost done. It seems to me that only one explanation will agree with all the facts I have mentioned. Questing’s murderer was a man with hobnailed boots. He threw the boots into Taupotapu. He had visited the Peak, for the boots correspond with Bell’s sketch of the prints. He had access to the reserve during the concert. He knew Questing was colour blind, and was most anxious that we should not discover this fact. He was an enemy agent and Questing knew it. Now what figure in our cast fits all these conditions?’

‘Eru Saul,’ said Dr Ackrington.

‘No,’ said Falls. ‘Herbert Smith.’

IV

It was Simon who was making the greatest outcry: Simon protesting that Bert Smith wouldn’t hurt a fly, that he couldn’t have done it, that he had tried to join up, that he was all right as long as he kept off the liquor. It was Simon who, with a helpless slackening of his voice, repeated that Falls had no right to bring this accusation and, finally, that Falls did it to protect himself. The Colonel and Dr Ackrington tried to silence him, Webley attempted to get him out of the room, but he held his ground and in the end he talked himself to a standstill. His lips trembled, he made a gesture of relinquishment. Like an exhausted child, he stumbled clumsily to a seat, beat the table with his fists, and at last was silent.

‘Smith!’ said Gaunt. ‘Lord, what an anticlimax! They must be hard-up for cogs in the fifth column set-up in this country if they found a job for Smith.’

‘I’m afraid he is a very small cog,’ replied Falls.

The Colonel said: ‘He’s been with us for years.’

‘I am not entirely convinced,’ said Dr Ackrington importantly. ‘How are you so damned positive that Smith knew Questing was colour blind? He may have believed the story of the sun screen.’