The Man who Staked the Stars by Katherine MacLean

In his luxurious hotel room Bryce checked his watch. Eight o'clock. A telephone call was scheduled for some time in the half hour. He filed the question of who was behind the night's attack and picked up the phone. The dial system was in automatic contact with any city in the world. He dialed.

Somewhere in a city, a phone rang. It rang unheard, for it was locked into a safe in a tiny rented office with some unusual mechanisms attached. The ringing was stopped abruptly and a recorded voice answered, "Yeah?"