From my own proceedings my thoughts turned to those of Thorndyke and his companions, though they were no affair of mine, or of Wallingford’s either, for that matter. Apparently the three men were going somewhere to make a post mortem examination. The presence of Dr. Barnwell suggested an analysis in addition; and the presence of Miller hinted at a criminal case of some kind. But it was not my case or Wallingford’s. For both of us the analyst had already done his worst.

While I reflected, I kept an eye on the passing landmarks, checking our route and idly trying to forecast our destination. From Chancery Lane we crossed Holborn and entered Gray’s Inn Road, at the bottom of which we swept round by King’s Cross into Pancras Road. At the end of this we turned up Great College Street, crossed Camden Road and presently passed along the Kentish Town Road. So far I had noted our progress with no more than a languid interest. It did not matter to me whither we were going. But when, at the Bull and Gate, we swept round into Highgate Road, my attention awoke; and when the taxi turned sharply at the Duke of St. Albans and entered Swain’s Lane, I sat up with a start. In a moment of sudden enlightenment, I realized what our destination must be; and the realization came upon me with the effect of a palpable blow. This lane, with its precipitous ascent at the upper end, was no ordinary thoroughfare. It was little more than an approach to the great cemetery whose crowded areas extended on either side of it; its traffic was almost completely limited to the mournful processions that crept up to the wide gates by the mortuary chapel. Indeed, on the very last occasion when I had ridden up this lane, my conveyance had been the mourning carriage which followed poor little Stella to her last home.

Before I had recovered from the shock of this discovery sufficiently to consider what it might mean, the taxi came to a sudden halt. I stepped out, and, looking up the lane, made out the shadowy form of Wallingford’s vehicle, already backing and manœuvring to turn round.

“Bloke in front has got out,” my driver announced in a hoarse whisper, and as he spoke, I caught sight of Wallingford—or at least of a human figure—lurking in the shadow of the trees by the railings on the right-hand side of the road. I paid off my driver (who, thereupon, backed on to the footway, turned and retired down the hill) and having waited for the other taxi to pass down, began slowly to ascend the lane, keeping in the shadow of the trees. Now that the two taxis were gone, Wallingford and I had the lane to ourselves, excepting where, in the distance ahead, the reflected light from the head-lamps of the car made a dim halo and the shape of the gothic chapel loomed indistinctly against the murky sky. I could see him quite plainly, and no doubt he was aware of my presence; at any rate, I did not propose to attempt any concealment, so far as he was concerned. His movements had ceased to be of any interest to me. My entire concern was with the party ahead and with the question at to what Thorndyke was doing at this time of night in Highgate Cemetery.

The burial ground is divided, as I have said, into two parts, which lie on either side of the lane; the old cemetery with its great gates and the large mortuary chapel, on the left or west side and the newer part on the right. To which of these two parts was Thorndyke bound? That was the question that I had to settle.

I continued to advance up the lane, keeping in the shadow, though it was a dark night and the precaution was hardly necessary. Presently I overtook Wallingford and passed him without either concealment or recognition on either side. I could now clearly make out the gable and pinnacles of the chapel and saw the car turn in the wide sweep and then extinguish its headlights. Presently, from the gate-house there emerged a party of men of whom some carried lanterns, by the light of which I could recognize Thorndyke and his three companions; and I noted that they appeared to have left their cases either in the car or elsewhere for they now carried nothing. They lingered for a minute or two at the wicket by the great gates; then, accompanied by a man whom I took to be the gate-keeper, they crossed the road to the gate of the eastern cemetery and were at once followed by another party of men, who trundled two wheel-barrows, loaded with some bulky objects the nature of which I could not make out. I watched them with growing anxiety and suspicion as they passed in at the gate; and when they had all entered and moved away along the main path, I came forth from the shadow and began to walk quickly up the lane.

The eastern cemetery adjoins Waterlow Park, from which it is separated by a low wall surmounted by tall railings, and this was my objective. The park was now, of course, closed for the night, locked up and deserted. So much the better. Locks and bars were no hindrance to me. I knew the neighbourhood of old. Every foot of the lane was familiar to me, though the houses that had grown up at the lower end had changed its aspect from that which I remembered when as a boy I had rambled through its leafy shades. On I strode, past the great gates on the left and the waiting car, within which I could see the driver dozing, past the white gatehouse on the right, up the steep hill until I came to the place where a tall oak fence encloses the park from the lane. Here I halted and took off my overcoat, for the six-foot fence is guarded at the top by a row of vicious hooks. Laying the folded overcoat across the top of the fence, I sprang up, sat for a moment astride and then dropped down into the enclosure.

I now stood in a sort of dry ditch between the fence and a steep bank, covered with bushes which rose to the level of the park. I had just taken down my overcoat and was putting it on before climbing the bank when its place was taken by another overcoat cast over from without. Then a pair of hands appeared, followed by the clatter of feet against the fence and the next moment I saw Wallingford astride of the top and looking down at me.

I still affected to be unaware of him, and, turning away, began to scramble up the bank, at the summit of which I pushed my way through the bushes, and, stepping over a three-foot fence, came out upon a by-path overshadowed by trees. Pausing for a moment to get my bearings and to mark out a route by which I could cross the park without coming into the open, where I might be seen by some watchful keeper, I started off towards a belt of trees just as Wallingford stepped over the dwarf fence and came out upon the path behind me.

The position was becoming absurd, though I was too agitated to appreciate its humour. I could not protest against his following me seeing that I had come in the first place to spy upon him, and was now, like himself, engaged in spying upon Thorndyke. However, he soon solved the difficulty by quickening his pace and overtaking me, when he asked in a quite matter-of-fact tone: