"I've been informed," Dowland said, "that the Overgovernment's scientists have been unable to make a practical use of YM because something has invariably gone wrong when they did try to use it. I also heard that there was no way of knowing in advance what would happen to make an experiment fail. But something always would happen, and frequently a number of people would get killed."
Camhorn nodded. "That is quite true."
"Well, then," Dowland said, "I think there is a race of beings who aren't quite in our time and space. They have YM and use it, and don't want anyone else to use it. They can tell when it's activated here, and use their own YM to interfere with it. Then another experiment suddenly turns into a failure.
"But they don't know yet who's using it. When the Trelawneys turned on their machine, these beings spotted the YM stress pattern back there in time. They went to that point and reinforced the time-blending effect with their own YM. The Trelawneys hadn't intended a complete contact with that first test. The aliens almost succeeded in blending the two periods completely in the area near the laboratory."
"For what purpose?" Camhorn asked.
"I think they're very anxious to get us located."
"With unfriendly intentions?"
"The ones we ran into didn't behave in a friendly manner. May I ask a question, sir?"
"Of course," Camhorn said.