The boys instinctively drew near. They imagined that they could hear each other's hearts beat, so tense was the silence.
He turned halfway around to glance at the boys.
"Is it anything serious?" asked Ned in a strained voice.
"I hope not. I can't tell you just yet. We shall know in a minute… Well, send some one for him," he snapped, answering something the man at the other end of the line had said to him. "Hello, hello! That you, Bob? Did Acomb tell you of our predicament? Yes. What I wanted to say was don't for goodness' sake send out the red car while the line is blocked."
"The red car," repeated Ned and Tad in one voice. Neither knew what it meant, but impressed them just the same.
"What, gone? gone?" groaned Phipps. "Are you sure? How long ago?
Ten minutes? Shut off the current! Quick! I hope so."
The assistant superintendent hung up the telephone deliberately and turned toward them.
The boys observed that his face was white and drawn.
"What, what is it?" asked Tad.
"There's a car of dynamite coming through the tunnel on the number two track," announced the young engineer calmly, thrusting both hands deep into his trousers pockets.