This time the roar which came to their ears was, perhaps, not so loud, and it seemed probable that it emanated from the guns of the defenders. But whoever was responsible for the firing, the enemy ringing in the city lost no time in replying. For these were the days of strenuous fighting about the beleaguered city. The allies, consisting of the Bulgarians, the Servians, the Montenegrins, and the Greeks, had swept the Turks in all directions before them, till the former were within striking distance of Constantinople itself, while such important cities as Salonica had been captured. But Adrianople still held out beneath the command of Shukri Pasha, while Scutari also resisted the Montenegrins. It may be imagined therefore, that the presence of a strong force of Turks in Adrianople made it essential that the allies should detach an even stronger force to watch and hem in their enemy. For weeks the armies had, in fact, watched one another, passage out of the beleaguered city being impossible, while actual fighting was intermittent and confined to mere skirmishing. But now pour-parlers between the allies and the enemy had broken down. Terms for peace had been rejected by the Ottomans, and as a consequence the war had been resumed after an armistice of some weeks' duration. To force the Turks to accede to the terms demanded by the allies, Adrianople must be taken, even at a great cost, and it happened that the arrival of Andrew Provost and his friends had coincided with this period. Indeed, a furious bombardment of the city was to begin forthwith, shells were to pour into the streets and about the houses, while the encircling forts were to be rushed one by one, at huge cost to the allies and the Turks, and the siege pressed daily closer. Here, then, was an explanation of this beginning cannonade. "Get down close to the wall," Dick called to his chum, as those answering guns opened and that same tell-tale shriek sounded in the distance. "Here come the shells. Hope they won't fall closer than formerly, for what has happened to the Commander may very well happen to us. Look out! Get down close. Wish to goodness there was a trench here in which we could shelter." In spite of the fact that a huge shell had just whizzed overhead, Dick went scuttling along beside the wall on hands and knees in search of some shelter. And hardly three minutes had passed before he was back again close to Alec. "There's a bit of a ditch close to the wall farther along there," he said hastily. "Let's carry the Commander there. Wait, though, till that beggar has passed us."