Then the omnibus crawled up.

I sprang on the foot-board and ascended to the roof, where I seated myself and surveyed the prospect to the rear.

No one else got on the omnibus--which had not stopped--and no cab or other passenger vehicle was in sight.

I continued to watch Thorndyke as he stood sentinel at the corner, and noted that no one appeared to be making any effort to overtake the omnibus.

Presently my colleague waved his hand to me and turned back towards Vauxhall, and I, having satisfied myself once more that no pursuing cab or hurrying foot-passenger was in sight, decided that our precautions had been unnecessary and settled myself in a rather more comfortable position..