"Well, in that case, we'd better be getting up to the station and see if they've discovered anything yet."
"Come along, then," I answered. "We must be quick though, for we've lost a lot of precious time, and every minute counts."
I took up the Evening Mercury and followed him out to the cab, after having sincerely thanked the hotel proprietor and the barman for their courtesy. The Inspector gave the driver his orders and we set off. As we went we discussed our next movements, and while we were doing so I idly glanced at the paper I held in my hand. There was a lamp in the cab, and the light showed me on the bottom right-hand corner a round blue india-rubber stamp mark, "W. E. Maxwell, stationer and newsagent, 23, Ipswell Street, Woolahra."
"Stop the cab!" I almost shouted. "Tell the man to drive us back to the Canary Bird quickly."
The order was given, the cab faced round, and in less than a minute we were on our way back.
"What's up now?" asked the astonished Inspector.
"Only that I believe I've got a clue," I cried.
I did not explain any further, and in five minutes we had brought the landlord downstairs again.
"I'm sorry to trouble you in this fashion," I cried, "but life and death depend on it. I want you to let me see No. 5 again."
He conducted us to the room, and once more the gas was lit. The small strip of envelope lay upon the table just as I had thrown it down. I seated myself and again looked closely at it. Then I sprang to my feet.