48529    How could he have permitted Sir Henry to fall in love with her?'

48530    'Sir Henry's falling in love could do no harm to anyone except Sir Henry.

48531    He took particular care that Sir Henry did not make love to her, as you have yourself observed.

48532    I repeat that the lady is his wife and not his sister.'

48533    'But why this elaborate deception?'

48534    'Because he foresaw that she would be very much more useful to him in the character of a free woman.'

48535    All my unspoken instincts, my vague suspicions, suddenly took shape and centred upon the naturalist.

48536    In that impassive, colourless man, with his straw hat and his butterfly-net, I seemed to see something terrible - a creature of infinite patience and craft, with a smiling face and a murderous heart.

48537    'It is he, then, who is our enemy - it is he who dogged us in London?'

48538    'So I read the riddle.'

48539    'And the warning - it must have come from her!'

48540    'Exactly.'

48541    The shape of some monstrous villainy, half seen, half guessed, loomed through the darkness which had girt me so long.

48542    'But are you sure of this, Holmes?

48543    How do you know that the woman is his wife?'