However, Mary deduced her own explanation for the singular initial. She, who was so very good at the business of numbers, concluded that the X is used as the unknown in mathematics, and that Tommo and Hawk were her two unknown factors. The letter X in calculations could be made to represent any number, and it was her duty to see that what it represented in her two sons was the sum of the very best she could do to make them men of whom she could be rightfully proud.

Mary smiled as she packed her basket in preparation for the boys' return. Then she bid the workmen goodnight, put on her warm coat, locked the cottage and walked over to the small bridge just below the falls, which she knew Tommo and Hawk must cross as they returned from the mountain.

Mary Abacus waited on the bridge and watched the water as it churned white at her feet. The thundering falls sent a fine mist into the air which created a rainbow in the late afternoon sunlight, and Mary could not imagine a more perfect moment. She was not to know that the magic mountain she loved so much had just swallowed up her precious children.

When the boys had not arrived by five o'clock she walked back to the office and found a lantern which had a good wick, and was well filled with the whale oil. Then she looked about and found half a loaf of bread, the remainder of the cheese she had given the boys and four apples. These she replaced in her basket together with several bandages and a bottle of iodine which she always kept on the premises. Then she took a small axe which hung behind the cottage door and this too she pushed, head first, into the basket. It was almost dark by the time Mary crossed the little bridge again, and set off along the path leading higher up the mountain.

There was only one path to the summit, though many hundreds of paths led from all over the mountain before converging on this main track, which was a forty-minute climb from the top. Mary determined that she would walk until the path which led from Strickland Falls intersected several others, a steady half-hour's walk up the mountain. The boys might have taken any of a dozen paths to arrive at this point, but she knew they must eventually turn into the one she now took for the journey home.

The trees became more dense as she climbed, and not more than twenty minutes after she had left it grew completely dark under the forest canopy. Mary stopped to light the lantern and then proceeded onwards. She had begun to call out, her voice echoing through the trees as she called their names.

Mary finally reached the intersection. It was getting cold so she gathered wood, a difficult task even with the help of the lantern, but she persisted until she had a large pile. She kept herself warm chopping the wood, stopping every minute or so to call out again. Finally she lit a fire and settled down to wait, hoping that if Tommo and Hawk were anywhere near they might smell the smoke or see the fire.

Though the night was cold it remained clear and no wind beyond the usual breeze stirred the tops of the trees. Mary told herself that this might not be the case at the summit, and Tommo and Hawk might have been caught in a change of weather and taken refuge in the hut. They were young, but it was unlikely they would do anything foolish. If the summit was suddenly to mist over they would know to stay put until morning. But in her heart Mary was terrified. She imagined a rock slide set in motion by the weight of the snow. She saw them venturing to the edge of a bluff, perhaps the mighty organ pipes, and the snow giving way and sending them crashing downwards nearly a thousand feet. She imagined any of a dozen incidents and all of them became vivid and concluded in her mind.

After two hours Mary knew that she would have to come down. Once again she lit the lantern, which she had put out to save the oil during her vigil by the fire. Wherever Tommo and Hawk were they could not descend in the dark, and she knew that no search party would set out to find them until first light. Mary set off down the path again and arrived at Strickland Falls nearly an hour later. She was scratched about and bleeding, for travelling a bush path at night is harrowing and her descent had been perilous. She had fallen on several occasions, though fortunately she had not lost the lantern. It took her another forty minutes to get back to the mill where Ikey and Jessamy were waiting, both of them terribly anxious. They'd already been up to Strickland Falls, and found it locked and had themselves not long been home.

Ikey had never seen Mary cry, but now she sat at the kitchen table and wept as she slowly spilled out the story. She blamed herself for letting the boys go, though Jessamy reminded her that they had roamed the slopes since they were four years old and the mountain was, in every sense, their own backyard.

At midnight Ikey left Jessamy asleep in an old armchair and Mary seated at the kitchen table with her head in her arms. Although she was tired and distraught almost beyond thinking, the ever-practical Mary had devised a rescue plan. She would make her appearance at Peter Degraves' saw mills at seven o'clock the following morning, when the timber cutters set off to work the slopes. But first she would call at the Degraves home and ask him for permission to pay his men a day's salary to send up a search party for Tommo and Hawk. They would set off from Strickland Falls so that if the children had spent the night safely in the hut on the summit they would be met along the path, not more than an hour and a half after first light. At this point the search would be over and the men, already on the mountain, could return to their work.

Mary was not foolish enough to suppose that this permission would be easily granted, for while her past employer was by the standards of the time a good man, he was tough and she knew he would expect her to pay for the value of the timber not produced while his men carried out the search. The loss of Tommo and Hawk would not be seen by him as a matter of great importance. Mary was of course, perfectly willing to meet his demands. The cost of a day's work of a hundred timber cutters would exhaust her available liquid resources, and possibly put her in debt to the brewer, but she cared not in the least about this.

Having resolved what to do at first light, she fell into a fitful sleep at the kitchen table only to be wakened an hour before dawn by Ikey.

'Come, my dear, I have brought help!' he said, shaking her gently by the shoulder.

Gathered in the street outside the Potato Factory were more than a hundred people. A more motley collection of the hopeless and forlorn would have been difficult to find anywhere in the South Seas. None among them would ever voluntarily have put one foot on the lowest slopes of the great mountain.

They were the drunks and whores, gamblers, pimps, touts, publicans' cellarmen, barmaids, whalemen and jack tars as well as other assorted human scrapings from the Hobart waterfront. Ann Gower, now the owner of a waterfront bawdy house, had taken a donkey cart and loaded herself upon it together with a large tea urn, so that she, too, might help.

Mary took one look at the crowd and knew Ikey must have finally gone senile. Though she perceived a handful of jack tars young enough to be useful, if the vast majority of this scraggy lot set foot upon the mountain, even on a cloudless summer day, few would return with every limb intact or even their lives, and most would be incapable of reaching the first tree line.

'Whatever has possessed you, Ikey Solomon?' Mary cried.

'My dear, I had thought to find some stout lads who might be persuaded to take on the search, but it is a great compliment to you that many felt that they should themselves come!'

After the initial shock, the sight of Ikey's caring volunteers lifted Mary's courage enormously. She thanked them for their generosity of spirit, but pointed out that the mountain was a dangerous and foreign place for most of them, and that they would more easily lose their own lives than help to find Tommo and Hawk.