At the wall enclosing the tower they paused while one opened the gate and then they passed within the enclosure, which, to the girl's horror, she found filled with headless bodies. The creature who carried the bodiless head now set its burden upon the ground and the latter immediately crawled toward one of the bodies that was lying near by. Some wandered stupidly to and fro, but this one lay still. It was a female. The head crawled to it and made its way to the shoulders where it settled itself. At once the body sprang lightly erect. Another of those who had accompanied them from the fields approached with the harness and collar that had been taken from the dead body that the head had formerly topped. The new body now appropriated these and the hands deftly adjusted them. The creature was now as good as before Tara of Helium had struck down its former body with her slim blade. But there was a difference. Before it had been male-now it was female. That, however, seemed to make no difference to the head. In fact, Tara of Helium had noticed during the scramble and the fight about her that sex differences seemed of little moment to her captors. Males and females had taken equal part in her pursuit, both were identically harnessed and both carried swords, and she had seen as many females as males draw their weapons at the moment that a quarrel between the two factions seemed imminent.

The girl was given but brief opportunity for further observation of the pitiful creatures in the enclosure as her captor, after having directed the others to return to the fields, led her toward the tower, which they entered, passing into an apartment about ten feet wide and twenty long, in one end of which was a stairway leading to an upper level and in the other an opening to a similar stairway leading downward. The chamber, though on a level with the ground, was brilliantly lighted by windows in its inner wall, the light coming from a circular court in the center of the tower. The walls of this court appeared to be faced with what resembled glazed, white tile and the whole interior of it was flooded with dazzling light, a fact which immediately explained to the girl the purpose of the glass prisms of which the domes were constructed. The stairways themselves were sufficient to cause remark, since in nearly all Barsoomian architecture inclined runways are utilized for purposes of communication between different levels, and especially is this true of the more ancient forms and of those of remote districts where fewer changes have come to alter the customs of antiquity.

Down the stairway her captor led Tara of Helium. Down and down through chambers still lighted from the brilliant well. Occasionally they passed others going in the opposite direction and these always stopped to examine the girl and ask questions of her captor.

«I know nothing but that she was found in the fields and that I caught her after a fight in which she slew two rykors and in which I slew a Moak, and that I take her to Luud, to whom, of course, she belongs. If Luud wishes to question her that is for Luud to do-not for me.» Thus always he answered the curious.

Presently they reached a room from which a circular tunnel led away from the tower, and into this the creature conducted her. The tunnel was some seven feet in diameter and flattened on the bottom to form a walk. For a hundred feet from the tower it was lined with the same tile-like material of the light well and amply illuminated by reflected light from that source. Beyond it was faced with stone of various shapes and sizes, neatly cut and fitted together-a very fine mosaic without a pattern. There were branches, too, and other tunnels which crossed this, and occasionally openings not more than a foot in diameter; these latter being usually close to the floor. Above each of these smaller openings was painted a different device, while upon the walls of the larger tunnels at all intersections and points of convergence hieroglyphics appeared. These the girl could not read though she guessed that they were the names of the tunnels, or notices indicating the points to which they led. She tried to study some of them out, but there was not a character that was familiar to her, which seemed strange, since, while the written languages of the various nations of Barsoom differ, it still is true that they have many characters and words in common.

She had tried to converse with her guard but he had not seemed inclined to talk with her and she had finally desisted. She could not but note that he had offered her no indignities, nor had he been either unnecessarily rough or in any way cruel. The fact that she had slain two of the bodies with her dagger had apparently aroused no animosity or desire for revenge in the minds of the strange heads that surmounted the bodies-even those whose bodies had been killed. She did not try to understand it, since she could not approach the peculiar relationship between the heads and the bodies of these creatures from the basis of any past knowledge or experience of her own. So far their treatment of her seemed to augur naught that might arouse her fears. Perhaps, after all, she had been fortunate to fall into the hands of these strange people, who might not only protect her from harm, but even aid her in returning to Helium. That they were repulsive and uncanny she could not forget, but if they meant her no harm she could, at least, overlook their repulsiveness. Renewed hope aroused within her a spirit of greater cheerfulness, and it was almost blithely now that she moved at the side of her weird companion. She even caught herself humming a gay little tune that was then popular in Helium. The creature at her side turned its expressionless eyes upon her.

«What is that noise that you are making?» it asked.

«I was but humming an air,» she replied.

«'Humming an air,'» he repeated. «I do not know what you mean; but do it again, I like it.»

This time she sang the words, while her companion listened intently. His face gave no indication of what was passing in that strange head. It was as devoid of expression as that of a spider. It reminded her of a spider. When she had finished he turned toward her again.

«That was different,» he said. «I liked that better, even, than the other. How do you do it?»

«Why,» she said, «it is singing. Do you not know what song is?»

«No,» he replied. «Tell me how you do it.»

«It is difficult to explain,» she told him, «since any explanation of it presupposes some knowledge of melody and of music, while your very question indicates that you have no knowledge of either.»

«No,» he said, «I do not know what you are talking about; but tell me how you do it.»

«It is merely the melodious modulations of my voice,» she explained. «Listen!» and again she sang.

«I do not understand,» he insisted; «but I like it. Could you teach me to do it?»

«I do not know, but I shall be glad to try.»

«We will see what Luud does with you,» he said. «If he does not want you I will keep you and you shall teach me to make sounds like that.»

At his request she sang again as they continued their way along the winding tunnel, which was now lighted by occasional bulbs which appeared to be similar to the radium bulbs with which she was familiar and which were common to all the nations of Barsoom, insofar as she knew, having been perfected at so remote a period that their very origin was lost in antiquity. They consist, usually, of a hemispherical bowl of heavy glass in which is packed a compound containing what, according to John Carter, must be radium. The bowl is then cemented into a metal plate with a heavily insulated back and the whole affair set in the masonry of wall or ceiling as desired, where it gives off light of greater or less intensity, according to the composition of the filling material, for an almost incalculable period of time.