It was a kind of large brougham, such as is used by some commercial travellers, the usual glass windows being replaced by wooden shutters intended to conceal the piles of sample-boxes, and the doors capable of being locked from outside with a railway key.
As I emerged from the house, the coachman unlocked the door and held it open.
"How long will the journey take ?" I asked, pausing with my foot on the step.
The coachman considered a moment or two and replied: "It took me, I should say, nigh upon half an hour to get here." This was pleasant hearing.

A half an hour each way and a half an hour at the patient's house.

At that rate it would be half-past ten before I was home again, and then it was quite probable that I should find some other untimely messenger waiting on the doorstep.

With a muttered anathema on the unknown Mr.Graves and the unrestful life of a locum tenens, I stepped into the uninviting vehicle.

Instantly the coachman slammed the door and turned the key, leaving me in total darkness.
One comfort was left to me; my pipe was in my pocket.