He had just reached the curtain to this apartment, when there came another puff of flame, followed by a shower of sparks.
Some of the sparks alighted on a table in the corner filled with chemicals.
There was an explosion almost immediately, and poor Bob was hurled backward, while the chemicals flew all around him.
The smoke was thick, and, completely bewildered, the lad could not tell which way to turn to reach the door.
Once he started, crawling on his hands and knees, and brought up directly opposite to where he wanted to go.
The smoke was every moment getting thicker, and it looked as if the brave youth was to die like a rat in a trap.
“I must get out somehow,” he muttered, desperately. “Why can’t I find the door?”
He turned, and, rising, made a dash forward.
“Help, help!”
The cry startled him. It came from the developing closet, and Bob recognized the voice as that of Mr. Starleigh.