Now the Checker swung right on Sheridan Road, where the cab soon pulled up in front of a big brick terra-cotta-trimmed six-flat apartment house-one of many such that stood shoulder-to-shoulder on this street-and let the blonde with the baby out.

My cab rolled on by, and when I looked back and saw the blonde disappear into the six-flat, I said, “Right here.”

The cabbie pulled over and craned around and showed me his gap-toothed grin again. “How’d I do?”

“Swell,” I said, and I took out a sawbuck, tore it in two and handed him half.

His eyes got wide; he wasn’t sure whether he should be pissed off or pleased. “What’s this?”

I was already getting out. “You get the other half by hanging around. Pull around the corner, there, and wait-but first find a phone and call Lt. Sapperstein at the Detective Bureau. Tell him I trailed Bernice Rogers to 4072 Sheridan, and want some backup.”

“Okay. Who’s the message from?”

“Heller.”

“Okay, Officer Heller.”

“Repeat all the names.”

“Uh-Lt. Sapperstein at the Detective Bureau. Bernice Rogers. Heller.”

“And the address?”

“4072 Sheridan.”

Now I gave him a smile. “Good man.”

The snow had stopped, but there was enough wind to blow it around some, a fine white mist that felt good on my face. My heart was starting to race and I breathed slow as I walked, calming myself. Across from the six-flat in question was one of the elaborate neighborhood movie palaces Chicago was so rich in. Arrowsmith was playing, with Ronald Colman. I hadn’t caught that one yet.

Same was true of the blonde, of course; hadn’t caught her yet, either. Inside the claustrophobic vestibule were half a dozen mailboxes and as many buzzers. All but one of the buzzers had a name underneath; neither “Bernice” nor “Rogers” was one of them. I pressed them all, except the nameless one-4-B-and waited for somebody to buzz the inner door open.