"We're all but done," said Burke tiredly, "and Keller's just about proved what the signals are."
"Can we go with you?" asked Sandy.
"Of course not," said Burke. "The first message was a distress call. It had to be. Only in a distress call would somebody go into details so any listener would know it was important. It called for help and said who needed it, and why, and where."
Pam turned to Holmes. "Can that air-lock be opened from outside?"
It couldn't. Not when it was fastened, as now.
"Somebody answered that call from Earth," said Burke heavily, "and the second message told more about what was wrong. The clickings, we think, are numbers that told how long help could be waited for, or something on that order. And then there was a beacon signal meant to lead whoever was coming to help to that place."
Keller smiled pleasantly at Pam. He made an electrical connection and zestfully checked the result.
"Now there's a third message," said Burke. "Time's running out for whoever needs whatever help is called for. The clickings that seem to be numbers have changed. The—what you might call the scale of reportage—is new. They're telling us just how long they can wait or just how bad their situation is. They're saying that time is running out and they're saying, 'Hurry!'"
There was a thumping sound. Only Sandy and Pam looked unsurprised. Burke stared.
Sandy said firmly, "That's the police, Joe. We've been going to the movies with people who want to talk about you. Yesterday one of them confided to us that you were dangerous, and since he told us to get away from the office, we did. There might be shooting. He tipped us a little while ago."