shakily. “I must have triggered off a bomb.”
As George glanced toward the wreck, she yelled, “Fire! The papers are on fire!”
Professor Titus had rushed to a nearby extinguisher and told the others to get another from the outer office. The flaming papers crackled and sent up greenish smoke. The two extinguishers failed to douse the flames.
“Notify the fire department!” Professor Titus shouted, and George dashed to the office phone to put in the call.
The odor from the burning contents of the cabinet became intolerable. Everyone was forced to leave and the door was closed. Professor Titus suddenly recalled that there was a manual sprinkler system in the ceiling of the lab. He turned two metal wheels on the wall, then opened the lab door a crack and peered in. Water was streaming down. By the time the firemen arrived, the blaze had been extinguished.
“I guess our equipment isn’t needed,” said one of the men with a smile, “but we’ll investigate the cause of the fire.”
Professor Titus looked a little sheepish. “I only remembered about the overhead sprinkler system after we called you,” he said. “What I think we do need here is an inspection by the police bomb squad.” He told about the explosion in the file cabinet, and the fire captain in charge telephoned at once to the head of the bomb squad.
Nancy remarked to the other girls, “If there was anything important in the file, it’s no good to us now.”
George replied, “I guess that’s the way the burglar planned it.”
Nancy turned to Professor Titus. “Please tell me all you know about Zapp Crosson.”
“Actually I know very little,” he replied. “Why? Do you—?” When the young detective did not offer to explain her interest in the graduate student, Professor Titus went on, “The young man was secretive and uncommunicative. Several times I tried to engage him in conversation, but all he ever told me was that his parents were foreign and he had had part of his education in Europe.”
Nancy said she understood that Crosson worked next to Ned in the lab.
“Yes,” Professor Titus said, “and he often assisted Ned, mostly when no regular classes were being held in the lab or when no other students were working there on experiments.”
At once Nancy thought, “Here’s a clue!” She wondered if Ned was doing original experiments. Was Crosson helping him or only being an inquisitive bystander?
At that moment two fully equipped representatives from the police bomb squad arrived. They entered the soaking wet lab and checked every inch of its walls and floor to be sure that no other bombs had been planted.
By this time the rank odor which had accompanied the fire had vanished up the ventilator and the fire captain declared the room was now safe to enter.
“I’d like to take a look around the place again,” Nancy told the professor.
“Go ahead,” he said. He introduced her to the bomb squad men and said she was an amateur detective. “But her methods seem very professional,” he added with a smile.
“Then we would be glad for any help you can give us,” one member of the squad said. “I’m Jake Reilly.”
Nancy grinned. “Thank you for the compliment,” she said. “I’m sure I can’t tell you well-trained men anything you wouldn’t be able to find out yourselves.”
Professor Titus spoke up quickly. With a grin he said, “The police have not yet found our students Ned Nickerson and Zapp Crosson. Miss Drew, on the other hand, has uncovered several leads.”
The men were very much interested. “Can you tell us about any of them?” Reilly asked the young detective.
Nancy took a deep breath before answering. “I’m afraid Professor Titus is exaggerating about my discoveries. I became involved in the case because of a strangely worded message I received in a robot copter. Actually it was a warning to me to beware of Cyclops.”
“Cyclops?” Reilly repeated. “What is that?”
“That’s what I’m