The valet entered.

Sypher explained.

He had a bad foot and wanted to see a doctor.

Did the valet know of a good doctor?
The valet not only knew of a good doctor, but an English doctor resident in Geneva who was always summoned to attend English and American visitors at the hotel; furthermore, he was in the hotel at that very moment.
"Ask him if he would kindly step up," said Sypher.
He looked ruefully at his ankle, which was about the size of his calf, wondering why the Cure had not effected its advertised magic.

The inflammation, however, clearly required medical advice.