It was possible, he discovered, to pass from the corridor of the basement flat, into the store room, and out through a door at the back of the building into a small courtyard.

Access to the street was secured through a fairly large door, placed there for the convenience of tenants who wished to get their coal and heavy stores delivered.

In the street behind the block of flats was a mews, consisting of about a dozen shut-up stables, all of which were rented by a taxicab company, and now used as a garage.
If the murder was committed in the flat, it was by this way the body would have been carried to the mews, and here, too, a car would attract little attention.

Inquiries made amongst employees of the cab company, some of whom occupied little rooms above their garages, elicited the important information that the car had been seen in the mews on the night of the murder--a fact, it seemed, which had been overlooked in the preliminary police investigations.
The car was a two-seater Daimler with a yellow body and a hood.

This was an exact description of Thornton Lyne's machine which had been found near the place where his body was discovered.