Until K-eighty-eighty blew him into little pieces Martino had been one of the West's greatest physicists. The Russians spent four months putting him together again and when they finally handed him back to the Americans he was as good as new - apart from the gleaming steel head they'd stuck on his shoulders. That was where the trouble began.

How could they be sure that this ball-bearing on legs was the old Martino? How could he go back to work on top-secret projects when, for all they knew, he might be a spy with a hot-line straight to the Kremlin?

Algis Budrys weaves a brilliant mystery around the half-metal man with the world's biggest identity crisis.