The Human Chord by Algernon Blackwood

I

But he was hardly settled there had not even been time to warm the sheets again when he was aware that the test, instead of being over, was, indeed, but just beginning; and the detail that conveyed this unwelcome knowledge to him, though small enough in itself, was yet fraught with a crowded cargo of new alarms. It was a step upon the staircase, approaching his room.