Of late Lavirotte's visits to Dora had been so infrequent and irregular that she did not know when to expect him, or when to be surprised that he did not come. Three or four days often passed now without her seeing him. She knew he was busy, exceedingly busy, at St. Prisca's Tower, but busy with what she could not tell. For the past few weeks he had always seemed to her exhausted and taciturn. There was no falling off in his tenderness towards her. He seemed to love her more passionately than ever. But his visits were short, and he said little. It was three days before Lavirotte got O'Donnell's last letter that he visited Dora. On going back from her to the tower he had thrown himself more blindly, more enthusiastically into the work of excavation than ever. In this final effort he had exhausted all his physical resources, with the result that when O'Donnell's letter came his strength was completely wasted, and he was as helpless as a little child. When he had seen Dora last he said he would come again soon--as soon as the important business upon which he was engaged would allow him. But he named no hour, no day. Three days passed and she did not see him or hear from him. That was not unusual. A fourth, a fifth, a sixth, a seventh day might go by without arousing anything stronger than longing and disappointment in her heart. Since she had come back from Ireland she had never passed the threshold of that solitary tower in Porter Street. He had never asked her to come, nor had her grandfather. Dominique had told her that matter of the first moment rested upon his uninterrupted attendance at the tower. He had taken her no further into his confidence. It would, he had said, be time enough to tell her all when all was known, and the hopes which moved him had been realised. Beyond Dora there was nobody else in London who had any distinct knowledge of where Lavirotte and the old man lived. It is true, of course, that they had to get food, but this Crawford always procured and brought into the tower, so that the likelihood was not a soul who supplied them with the necessaries of life had any distinct memory as to where they lived. And even if the people knew where they lived, there was no reason in the world why they should be uneasy because a certain old man who had for some time back bought milk, or bread, or meat of them ceased to come any more. It might be he had left the place. It might be he had taken his custom somewhere else. It might be he was dead in the ordinary and familiar ways of death, which require no extraordinary comment and exact no extraordinary cares. Among the four millions of people who live within the mighty circle called London, it was unlikely one would take the trouble to inquire what had become of Crawford and Lavirotte. Dora naturally would; but her grandfather had visited her in Charterhouse Square only two or three times since they had come back from Ireland. She had no reason to expect a visit from him for one week, two weeks, three weeks. Nor had she any reason to feel uneasy if Dominique did not come to Charterhouse Square for several days. Meanwhile, what was to become of him, Lavirotte? While the candle yet burned he had made out that there was only one door into this vault, and that in the direction of what had formerly been the body of the church. Crawford had told him that the ordinary entrance to that vault had been from the crypt of the church, but that with the destruction of the church the crypt had been destroyed, and now a solid bank of masonry and earth, thirty or forty feet thick, forming the lane at the back, lay between the vault and the cellars of the stores beyond. So long as the candle had lasted he did not seem to have severed his last connection with the earth above; but with the absolute darkness following the failure of the light, all the realities of the tomb, without the merciful absence of suffering, had come upon him. He was buried, and yet free to move. He could walk about, and yet the great tower standing over him was little better than a large headstone on his grave. He had committed no crime, and yet was condemned to die--to die the slowest and most painful of all deaths--by want of water. He had read about the Black Hole of Calcutta. This place was about the size of that terrible dungeon. But how much better it would have been to die there a hundred years ago, surrounded by fellow-men--to die there quickly, in the distance of time between evening and day, instead of dragging out here, hour by hour, minute by minute, the terrible solitude of doom foreclosed. It had been a very hot summer, and now the autumn was at hand. The leaves had taken their earliest shade of yellow, and when the wind blew strongly the sicklier leaves fell. For months in London a fierce sun and a dry air had parched all they touched. Nails in woodwork exposed to the sun had worked loose in their holds. It was the beginning of September, and people, thinking of a calamity which occurred more than two hundred years ago, said it was a mercy London was no longer built of wood; since if it was, and the fire should then break out with a strong wind behind it--as at the time of the Great Fire--what was now called the Great Fire would cease to be so named, and be referred to as the Little Fire compared with the gigantic proportions which a burning wooden London of to-day would afford. Crawford and Lavirotte had, owing to the dryness of the season, been able to get rid of the excavated earth by exposing it to the heat on the roof of the tower, and then casting it, handful by handful, through the embrasures. Although no food ever was sent by tradespeople in the vicinity to the tower, it was generally known by the men who worked there that two men visited the tower. But why they lived there, or what their occupation was, no one knew. They had been seen to come in and go out. That was all. When Lavirotte made up his mind that their means of making away with what they dug was out of proportion with his desire of getting downward, he had resolved to trust the lofts to a greater weight than had hitherto been put upon them; and finding loft number one but slightly cumbered with the larger stones Crawford could not dispose of, he had determined to make it the chief depository of the excavated earth. Over and over again Crawford had told him the lofts were old, the beams rotten. He had ignored the warning, saying if they were to win at all they must win quickly, and that he would risk everything but delay. As the weight of earth upon the first loft increased, it gradually sank in the middle. Lavirotte, cautioned by this, tried to find out the absolute condition of the beams, and to his great joy discovered, after carefully probing them, while slung under them in a loop of line, that they were comparatively sound. But the hotter the weather became, and the greater the burden upon the floor above grew, the more the joists bent downward. He did not care. He was certain the joists would not break. They showed no sign of chipping or splitting, and, in perfect fearlessness, he went on piling up the clay, taking, of course, the ordinary precaution to keep the weight as close as possible to the wall. Gradually, however, owing to the inclination towards the centre, the clay slid slightly inward, and, as it dried in the hot air of August, the inner surface of the clay fell inward. Before leaving the tower, the morning he got O'Donnell's letter, Lavirotte looked anxiously at the floor of the first loft. It was now concave above, convex below. But although he looked long and anxiously, he could see no sign of any of the joists giving way. "They will bend like yew," he said. "They will never break." He had omitted one calculation, that when they had bent to a certain degree, they would be withdrawn to a certain extent from their holdfasts in the wall, and when they were withdrawn from their holdfasts beyond a certain extent, they would slip out. On the morning of the day after Lavirotte was entombed in the vault beneath St. Prisca's Tower, the joists of loft number one had been so far withdrawn from their supports in the wall that the loft was in equilibrio, and ten pounds more pressure on the floor would drag the whole loft down with all its burden into the hole beneath.