The detective could not understand why there should be this separate storeroom until he had examined a long tank at one end, and found that it was an ammonia generator, with an engine underneath.
“They used to make artificial ice here, I see,” muttered Nick Carter.
He walked very softly across the floor, because he was convinced that in the room below there were persons who would come after him quickly if they were aware of his presence.
In a corner of this second room was a sort of vestibule, with two doors.
It was easy to open these doors, for neither was locked.
The detective found himself at the top of a long flight of stairs which turned sharply not far from the bottom.
From where he stood he could look down into what appeared to be an office, furnished with a roll-top desk and a chair.
There was other furniture, no doubt. But the desk and chair were all Nick could see, except the old linoleum with which the floor was covered.
Low voices came to him—so low that if his ears had not been sharper than those of most people, he would not have been able to make out what was being said.
As it was, he not only caught the words, but also he recognized the voices as those of Don Solado and Prince Miguel.