ffices on 112th
Street, there was one door marked "M. R. Gabriel." Behind that door was
his private secretary's office, which acted as an effective barrier
between himself and the various employees of the firm. Behind the
secretary's office was his own office.

There was still another door in his inner office, a plain, unmarked door
that looked as though it might conceal a closet.

It didn't. It was the door to a veddy, veddy expensive apartment with
equally expensive appointments. One wall, thirty feet long and ten feet
high, was a nearly invisible, dustproof slab of polished, optically flat
glass that gave the observer the feeling that there was nothing between
him and the city street, five hundred feet below.

The lights of the city, coming through the wall, gave the room plenty of
illumination after sunset, but the simple flick of a switch could
polarize it black, allowing perfect privacy.

The furniture was massive, heavily braced, and well upholstered. It had
to be; Mike the Angel liked to flop into chairs, and his two hundred and
sixty pounds gave chairs a lot of punishment.

On one of the opaque walls was Dali's original "Eucharist," with its
muffled, robed figures looking oddly luminous in the queer combination
of city lights and interior illumination. Farther back, a Valois gleamed
metallically above the shadowed bas-reliefs of its depths.

It was the kind of apartment Mike the Angel liked. He could sleep, if
necessary, on a park bench or in a trench, but he didn't see any reason
for doing so if he could sleep on a five-hundred-dollar floater.

As he had passed through each door, he had checked them carefully. His
electrokey had a special circuit that lighted up a tiny glow lamp in the
key handle if the lock had been tampered with. None of them had.

He opened the final door, went into his apartment, and locked the door
behind him, as he had locked the others. Then he turned on the lights,
peeled off his raincoat, and plopped himself into a chair to unwrap the
microcryotron stack he had picked up at Harry's.

Theoretically, Harry wasn't supposed to sell the things. They were still
difficult to make, and they were supposed to be used only by persons who
were authorized to build robot brains, since that's what the stack
was--a part of a robot brain. Mike could have put his hands on one
legally, provided he'd wanted to wait for six or eight months to clear
up the red tape. Actually, the big robotics comp