The bombardment of Belgrade had begun again. Some plan of campaign was being followed out that had to do with either the utter destruction of the city or else the rout of its defenders, so that a hostile army could make the crossing in safety, something they did not dare attempt as long as the Serbs remained in their trenches awaiting their coming.
The mere fact of its being night made no difference. Long ago the Austrians had undoubtedly platted everything out and secured the range for their big guns on the heights back of the river. They could fire just as accurately in utter darkness as in broad daylight, for the shells were hurled with mathematical precision, each one being timed to explode at a certain second.
As if that first shot were looked upon as a defiance, several Serb guns took up the challenge. It was inspiring to see the shells burst like giant skyrockets far up on the heights. Evidently others besides the Austrians had occupied their spare time in getting distances all down to a fine point, for the Serbian gunners managed to drop their projectiles in given places, where they threatened to smash some of the tremendous war engines of the enemy.
The boys knew that it was much too late for them to think of turning back now. In fact, such a thing was utterly impossible, much as they might have wished it. All they could do was to keep on floating down the river, trusting in their customary good luck to escape harm.
They could hear strange noises as the reverberations died out, which Jack knew must be made by the whizzing shells far above them. It gave him a thrill to realize the fact that he and his three chums were thus brought into the very whirlwind of war, with deadly engines of destruction busy on all sides of them.
Even the anchored monitor several miles up the river joined in the music, for that partly muffled roar seemed to come from the direction they knew her to be in.
The two passengers had remained perfectly silent all this while, though their faces kept turned toward the spot where they knew the darkened city must lie. It was easy for Jack to imagine what their thoughts must be at such a time as this. No one could say how long this bombardment had been going on, or what sort of damage the terrible shells exploding may have done among the numerous fine buildings of the Serbian capital.
By now it might be lying a mass of ruins for aught they knew; and somewhere in the midst their mother had been living the last they heard from her. Yes, Jack could easily appreciate what agonies of mind the couple must be enduring as they crouched there in each other’s arms, and with throbbing hearts listened to the hoarse crash of the opposing guns, the one friendly and the other freighted with hatred and animosity.
There was, of course, no danger to the party on the motorboat from the shells that were passing so high overhead, describing a parabola in their flight, something after the manner of a rainbow. Jack’s fears were along other lines.