The Chief nodded gravely. “Probably the biggest I’ve ever asked you to handle.”

“You’d better tell me about it.”

The Chief leaned back in his chair. “What would you say was the gravest international problem at the moment – the Bomb?”

Chavasse shook his head. “No, I don’t think so. Not anymore, anyway. Probably the space race.”

The Chief nodded. “I agree, and the fact that John Glenn and those who have followed him have successfully emulated Gagarin and Titov has got our Russian friends worried. The gap is narrowing – and they know it.”

“Is there anything they can do about it?” Chavasse said.

The Chief nodded. “Indeed there is, and they’ve been working on it for too damned long already – but perhaps Professor Craig would like to tell you about it. He’s the expert.”

Professor Craig took off his spectacles and started to polish their lenses with the handkerchief from his breast pocket. “The great problem is propulsion, Mr. Chavasse. Bigger and better rockets just aren’t the answer, not when it comes to travelling to the moon, and anything farther involves immense distances.”

“And presumably the Russians have got something?” Chavasse said.

Craig shook his head. “Not yet, but I think they may be very near it. Since 1956, they’ve been experimenting with an ionic rocket drive using energy emitted by stars as the motive force.”

“It sounds rather like something out of a science-fiction story,” Chavasse said.

“I only wish it were, young man,” Professor Craig said gravely. “Unfortunately it’s hard fact, and if we don’t come up with another answer quickly we might as well throw in the towel.”

“And presumably, there is another answer?” Chavasse said softly.