Satisfied so far with the play he was staging, Kennedy moved over to the hotel desk, and after a quiet conference with the head clerk, found out that the room next to the suite of the Mendozas was empty. The clerk gave him several keys and with a last look at the Señora and her son, to see whether they were getting restive, I followed Craig into the elevator and we rode up to the eighth floor again.
The halls were deserted now and we entered the room next to the Mendozas without being observed. It was a simple matter after that to open a rather heavy door that communicated between the two suites.
Instead of switching on the light, Kennedy first looked about carefully until he was assured that no one was there. Quickly he sprinkled on the floor from the hall door to the table on which the case of cigarettes lay some of the powder which I had seen him wrap up in the laboratory before we left. Then with the atomizer he sprayed over it something that had a pungent, familiar odor, walking backwards from the hall door as he did so.
"Don't you want more light?" I asked, starting to cross to a window to raise a shade to let the moonlight stream in.
"Don't walk on it, Walter," he whispered, pushing me back. "First I sprinkled some powdered iodine and then ammonia enough to moisten it. It evaporates quickly, leaving what I call my anti-burglar powder."
He had finished his work and now the evening wind was blowing away the slight fumes that had risen. For a few moments he left the door into the next room open to clear away the odor, then quietly closed it, but did not lock it.
In the darkness we settled ourselves now for a vigil that was to last we knew not how long. Neither of us spoke as we half crouched in the shadow of the next room, listening.
Slowly the time passed. Would anyone take advantage of the opportunity to tamper with that box of cigarettes on Mendoza's table? Who was it who had conceived and executed this devilish plot? What was the purpose back of it all?
Once or twice we heard the elevator door clang and waited expectantly, but nothing happened. I began to wonder whether if someone had a pass-key to the Mendoza suite we could hear them enter. The outside hall was thickly carpeted and deadened every footfall if one exercised only reasonable caution.
"Don't you think we might leave the door ajar a little?" I suggested anxiously.