They'd wait in the lobby, then get taken back to an exam room where they'd wait a few more hours... and at some point he'd see them.
Until one night.
I was the neurology resident on call, and around 11:00 that night was paged by the head of the hospital's janitorial services.
Apparently, Dr. Bond's 4:45 patient had been put in a room... and forgotten. The staff left around 6:00, and the patient, used to Dr. Bond's usual waiting times, just stayed in there. Eventually he fell asleep (the badly-rattled cleaning lady actually thought she'd found a body).
So I walked across the street to the clinic (not exactly a great idea in that area) and briefly met with the patient. After determining that he wasn't dead (he'd just left his hearing aids at home) I called Dr. Bond to ask him what to do.
To his credit, he drove in to see the patient for the regular appointment that had been scheduled for that afternoon.