Carthage had no intention of allowing these attacks to pass without retaliation. A large force, amounting at the lowest estimate to 100,000 men, was levied in Africa and landed in Sicily, where it received an accession of another 30,000. Himilco, who had commanded in the last campaign, was made general-in-chief. He conceived a novel and bold plan of campaign. He marched to north-eastern Sicily, a part of the Island which up to that time had been exempt from attack. Messana was his objective point, and Messana was almost helpless. It had walls, indeed, but these were in repair so bad that they were useless for any real defence. And then a considerable part of the army was with Dionysius and the Syracusans. What was left boldly confronted the enemy in the field. Himilco did not offer them battle, but embarking a considerable force in the ships which moved along the coast as the enemy advanced, made a direct attack on the town. He calculated that the ships would outstrip the Messanian army, and he proved to be right. The Carthaginians found the place almost deserted, and simply poured into the town by the gaps in the walls. The forts he could not take. Some of the inhabitants were slain in a hopeless attempt to hold the town; some attempted the desperate expedient of swimming across the Strait of Scylla and Charybdis, whose terrors were not so formidable as the ferocity of the Carthaginians--out of two hundred swimmers fifty got safe to the Italian side. Messana gained, Himilco marched on Syracuse, intending to take Catana on his way. The army was to follow the line of the seashore; the fleet was to keep on a level with it. At Ætna a diversion had to be made. The volcano was in action, and the streams of lava that flowed down the eastern slope compelled the army to make a _détour_ to the west. Dionysius thought he saw his opportunity in this division of the invading force. He put both his army and his fleet in motion, and proceeded to meet the enemy. Only the fleets, however, came into collision, and the result was a serious defeat of the Syracusans. The admiral, Leptines by name, had been strictly enjoined to be cautious; to keep his fleet in close order, and on no account to break the line. This tactic did not suit him. He attacked the enemy with a squadron of thirty quick-moving ships, at first with brilliant success. Then what the more prudent Dionysius had feared came to pass. Leptines could not hold his own against the overpowering numbers of the enemy. After some hours of fighting he had to make his escape with what ships were left to him. He had lost a hundred ships and, it was said, as many as twenty thousand men.