Mary and Brenda stop by a store to make a phone call. Mary, sassy as ever, hectors the man hogging the phone, Tim Nolan (Walter Pidgeon). He doesn't mind, in fact he rather takes a shine to Brenda. But she resists his efforts to get to know her, wanting no part of a new male friendship.
Then ... Tim is a determined man and he manages to find out her address. He pulls up across the street from her apartment on Lombard Street. With Angel Island and Pier 37 lining up in the distance, this must be the junction with the north end of Kearny (map).
... and Now, This block of Kearny has been developed quite a bit since then, including these houses, but Angel Island and the site of the demolished pier 37, now a marina, are still visible from here.
Then ... Tim looks up to her apartment on the top floor of 301 Lombard Street at the base of Telegraph Hill ....
... and Now, it's been over 70 years but you'd hardly know it comparing the houses today.
Then ... As Tim wonders how best he should make contact a deliveryman arrives and calls Brenda from an outside phone. She buzzes the door open for him and before it closes Tim urges his dog Smitty to follow the man. He then returns home and, craftily, awaits a call from Brenda.
... and Now, here's the same, identical, front door today. (By the way, check out the gawkers reflected in the doorway glass above, watching the scene being filmed).
Then ... Sure enough, Brenda reads the dog's name tag and calls the phone number on it (Tim's). When he shows up she's taken aback and accuses him of dirty tricks but he sweet talks her into a date (face it, how could she resist Walter Pidgeon's voice, one of the most mellifluous in the business?).
... and Now, CitySleuth has explained earlier that the apartment scenes were filmed in a studio using photo and projected video backgrounds for the views. The window view above is a photo plate of Yerba Buena Island and part of the Bay Bridge span taken from the Coit Tower parking lot at Pioneer Park. From that same location today trees block that view but here's how it looks from close by at the top of Telegraph Hill Boulevard.