The city was well hidden. The observers on the ships could see nothing but the usual jungle and the waterways.
Yet the Dhulhulikh, under torture, had said that there must be thirty-five thousand living beings there. They had sworn that six thousand and five hundred warriors could swarm up from The Tree to defend the city.
The flagship continued to sink and then, carried toward the trunk by the wind piling against its massive broadside, it moved over a branch five hundred feet below.
Ulysses said, "Bombardiers, fire when ready!"
He glanced at his port. The trunk seemed to be rushing toward them so swiftly that he had to repress a desire to order the ship to turn away. He had made his calculations, and they should be past the trunk by a hundred yards before the wind took them northward.
The bomb hatches had been opened, and the bombardiers, all humans, waited until their sights were on the target.
Ulysses waited. Graushpaz, behind him, shifted. His stomach rumbled, and his proboscis, waving nervously, touched Ulysses' shoulder with its two wet tendrils. Ulysses shuddered.
"Bombs away," the bombardier reported. The ship immediately lifted as the weight fell out. Ulysses looked out of the side port. The dark teardrops were still falling. Some missed the branch and continued on to the one below it. About ten struck. Fire gouted up, and great chunks of wood came flying through the fire and the black smoke. There were sections of the smaller trees that grew on The Tree, and some things that could have been small bodies. But whether they were animals or winged men could not be determined.
The two ships behind them also dropped their load and at once danced upward with relief.
Enough of their bombs struck at the same place as the first load to dig huge holes into the branch. But the limb was a long way from being weakened enough to break off. Besides, even if it was severed, it would not fall. There were too many vertical branches growing beneath it. It was possible that it would have remained suspended if all its vertical growths had been taken away. The vine complexes linking it to other branches and to trunks might have held it up. However, the chunks blasted out had opened the way for the riverlet, which now spilled out and over the sides, down the trunk and on to a branch about three hundred feet below it.
Ulysses had known that the entire fire-bomb power of the fleet would be required to sever a branch. He was not after that. He only wished to shake out the hidden Dhulhulikh. Once he knew where they were hidden, he would attack those places.
The big dirigible made a wide circle around the trunk and entered into the pattern just after the final ship of the ten had released its bombs. This time, he gave the orders that dipped the nose of the craft and sent it under the blasted branch. The men in the cockpits on top of the vessel reported that the water from the riverlet was falling down on them. And then the ship had passed under and there was, a moment later, a number of explosions as bombs struck the branch beneath the ship. Some of these were composed of jellied alcohol and burned furiously, sending up a huge cloud of smoke.
There was still no sign of the Dhulhulikh.
Ulysses gave the order to save the bombs for a while. He took the flagship around again, this time flying it even lower, though at a greater distance from the trunk. The wind was much reduced here, and so the airship could manoeuvre with more safety. But even so the distance between the two branches through which theBlue Spirit slid was only two hundred feet. No bombs were released. Ulysses did not want the ship to lift up and possibly rub against the upper branch.
At this point, the air was alive with birds. The explosions and the great droning vessels had scared out all the animal life for miles around. A number of the birds hit the propellers, and blood was splattered over the sides of the ship in the immediate neighbourhood. Other birds rammed into the skin of the ship or into the glass of the control gondola ports.
Ulysses was too intent on the steering of the ship to inspect the intensely convoluted and wrinkled surface of The Tree for an opening to the city. But as the ship began to turn in a relatively wide space between trunks, he heard Awina gasp.
"There's an opening!" she said.
"Steady as she goes," he told the steersman.
Under the branch ahead was a cavernous hole. It was oval and about a hundred feet across. Shadowed by the branch, its dark interior seemed empty. But Ulysses was sure that there must be many bat-men crowded into it. They would be waiting, until they were sure that the entrance had been detected, and then they would act. Or their commander might decide it would be better to take the offensive.
Graushpaz said, "There's another hole!"
He pointed at a dark oval under a branch in the trunk on their right.
The ship would be passing between the two holes, which meant that it could be attacked from both sides simultaneously.
Ulysses had this information transmitted to the other ships and then ordered them not to follow the flagship but to rise and circle. He was taking a chance by bringing his vessel to a place where the bat-men could get above him. They had bombs now, and it would only take one to blast a hole in the thin skin and another through the hole to turn theBlue Spirit into a burning, falling wreck.
He spoke again into the radio box to the rocketeers stationed on the blisters on the sides of the craft and in the cockpits on top. A minute later, as the airship slid by the holes at ten miles per hour, dark objects spurting flame and smoke soared toward the holes from the dirigible. Several struck outside the entrances, but five went into one and three into another. Each had a warhead of ten pounds of plastic explosive and one pound of black gunpowder and a detonating cap of picric acid.
Flames and black smoke belched out of the mouths of the entrances. Bodies came flying out, and then the ship had passed the holes. A moment later, winged men jumped out of the holes, fell, began flapping and then tried to catch up with the dirigible. They continued to stream out incessantly.
At the same time, the Dhulhulikh appeared from holes previously unseen, and the vine complexes yielded hundreds of bat-men.
The second volley of rockets hit the nearest holes again and caught many within them. A dirigible, flying over a gigantic vine complex, dropped time bombs at the junction of the complex and a branch. These tore loose the moorings on one side, causing the tangle to drop to a vertical position. At least a thousand bodies fell from the vines, although most of these began to fly back up. A majority of these were women and children.
Awina pulled at Ulysses' arm and pointed to the starboard at a downward angle. "There!" she said. "There! Under the third branch down! There is an immense hole!"
Ulysses saw it, too, just before the ship's passage took the hole away around the curve of the trunk. This hole was triangular and looked as if it were hundred yards across. Out of it, in unending files, stepped forty bat-men abreast. They marched in strict parade step, sprang together off the edge of the hole, fell, raised and lowered their wings, checked their fall, and then began climbing upward. They did not attempt to catch the dirigible, as the others had done, but flew upward as if toward a rendezvous.
Probably they were intent on getting as high as they could and would then form to attack.
Ulysses gave the order to put the dirigibles in battle formation at some distance above the height attainable by the Dhulhulikh. This manoeuvre took fifteen minutes. The ships had to gain altitude and at the same time make a circle which would bring them all together and facing the opposite way. Then, the flagship half a length in the lead, the fleet proceeded against the cloud of bat-men flying around and around the trunk just below the base of the mushroom-shaped top.