When the hole reached to about halfway between the top of the arch and the tower, Robert and Cyril let themselves down cautiously on the inside, and lit matches. How thankful they felt then that they had a sensible father, who did not forbid them to carry matches, as some boys’ fathers do. The father of Robert and Cyril only insisted on the matches being of the kind that strike only on the box.

‘It’s not a door, it’s a sort of tunnel,’ Robert cried to the girls, after the first match had flared up, flickered, and gone out. ‘Stand off—we’ll push some more stones down!’

They did, amid deep excitement. And now the stone heap was almost gone—and before them the girls saw the dark archway leading to unknown things. All doubts and fears as to getting home were forgotten in this thrilling moment. It was like Monte Cristo—it was like—

‘I say,’ cried Anthea, suddenly, ‘come out! There’s always bad air in places that have been shut up. It makes your torches go out, and then you die. It’s called fire-damp, I believe. Come out, I tell you.’

The urgency of her tone actually brought the boys out—and then every one took up its jacket and fanned the dark arch with it, so as to make the air fresh inside. When Anthea thought the air inside ‘must be freshened by now,’ Cyril led the way into the arch.

The girls followed, and Robert came last, because Jane refused to tail the procession lest ‘something’ should come in after her, and catch at her from behind. Cyril advanced cautiously, lighting match after match, and peering before him.

‘It’s a vaulting roof,’ he said, ‘and it’s all stone—all right, Panther, don’t keep pulling at my jacket! The air must be all right because of the matches, silly, and there are—look out—there are steps down.’

‘Oh, don’t let’s go any farther,’ said Jane, in an agony of reluctance (a very painful thing, by the way, to be in). ‘I’m sure there are snakes, or dens of lions, or something. Do let’s go back, and come some other time, with candles, and bellows for the fire-damp.’

‘Let me get in front of you, then,’ said the stern voice of Robert, from behind. ‘This is exactly the place for buried treasure, and I’m going on, anyway; you can stay behind if you like.’

And then, of course, Jane consented to go on.