"No; I think these ropes will do very well till your friends the police
bring the handcuffs."

Father Brown, who had been looking dully at the carpet, lifted his round
face and said: "What do you mean?"

The man of science had picked up the peculiar dagger-sword from the
carpet and was examining it intently as he answered:

"Because you find Mr Todhunter tied up," he said, "you all jump to the
conclusion that Mr Glass had tied him up; and then, I suppose, escaped.
There are four objections to this: First, why should a gentleman so
dressy as our friend Glass leave his hat behind him, if he left of his
own free will? Second," he continued, moving towards the window, "this
is the only exit, and it is locked on the inside. Third, this blade
here has a tiny touch of blood at the point, but there is no wound on Mr
Todhunter. Mr Glass took that wound away with him, dead or alive. Add
to all this primary probability. It is much more likely that the
blackmailed person would try to kill his incubus, rather than that the
blackmailer would try to kill the goose that lays his golden egg. There,
I think, we have a pretty complete story."

"But the ropes?" inquired the priest, whose eyes had remained open with
a rather vacant admiration.

"Ah, the ropes," said the expert with a singular intonation. "Miss
MacNab very much wanted to know why I did not set Mr Todhunter free from
his ropes. Well, I will tell her. I did not do it because Mr Todhunter
can set himself free from them at any minute he chooses."

"What?" cried the audience on quite different notes of astonishment.

"I have looked at all the knots on Mr Todhunter," reiterated Hood
quietly. "I happen to know something about knots; they are quite a
branch of criminal science. Every one of those knots he has made himself
and could loosen himself; not one of them would have been made by an
enemy really trying to pinion him. The whole of this affair of the
ropes is a clever fake, to make us think him the victim of the struggle
instead of the wretched Glass, whose corpse may be hidden in the garden
or stuffed up the chimney."

There was a rather depressed silence; the room was darkening, the
sea-blighted boughs of the garden trees looked leaner and blacker than
ever, yet they seemed to have come nearer to the window. One could
almost fancy they were sea-monsters like krakens or cuttlefish, writhing
polypi who had crawled up from the sea to see the end of this tragedy,
even as