word. In that case vent could be a contraction for no other word but 'ventilator,' in accordance with the sense of the words. So I concluded that the meaning of the whole sentence was simply this: 'The plunder is in the ventilator, the loss is discovered, take away the booty at once; Martin Hewitt is here, and I fear I may be watched.' There is the reading, and our little adventure this evening is what it has led to.

"Of course, the confederate wouldn't go groping about the squares so painfully as I have had to do. To him the reading would be simple enough, for the order of the moves would be preconcerted. Each of the conspirators would have, as a guide, both to reading and writing the cypher, a drawn set of squares, numbered in the order of the moves—1 where we have the i, 2 where we have the n, 3 where we have the v, and so on. With that before him, either reading or writing in this extraordinary cryptogram would be easy and quick enough. And now for Scotland Yard!"