Arrowsmith by Sinclair Lewis

The boy raised his head, cocked his inquisitive brow. On the stairway was the cumbersome step of Doc Vickerson. The Doc was sober! Martin would not have to help him into bed.

But it was a bad sign that the Doc should first go down the hall to his bedroom. The boy listened sharply. He heard the Doc open the lower part of the washstand, where he kept his bottle of Jamaica rum. After a long gurgle the invisible Doc put away the bottle and decisively kicked the doors shut. Still good. Only one drink. If he came into the consultation room at once, he would be safe. But he was still standing in the bedroom. Martin sighed as the washstand doors were hastily opened again, as he heard another gurgle and a third.