Presently they were approaching the opposite side of the building, having circled the interior court and light wells. They came to another trap-door, a twin of the one by which they had ascended.
Simpson was about to open this second trap when Rockwell spoke:
"Wait a minute!"
Stooping lower and lower till at last he seemed to be almost sitting on his heels as he walked, he made his way to the edge of the roof on the new street and peeped over the parapet--a dozen feet perhaps beyond the trapdoor. For a moment only he looked, then returned in the same cautious and laborious manner.
"We were right," he said to Simpson.
"Watchers?" Simpson asked.
"Two of them. And half way down the block a taxi."
But now Simpson was carefully raising the trap-door. After listening for a minute he put his head down and looked.
"Coast is clear," he reported.
"Go ahead, then," said Rockwell.