On April 7 the smoke of a steamer was seen in the distance, and it soon seemed to indicate that the Pampero was being pursued. Her course was changed, and she either succeeded in outdistancing her pursuer, or the latter decided that a mistake had been made in the identity of the vessel, and abandoned the chase. The expedition neared Key West, and they expected to find there United States vessels of war, and a strong garrison. Therefore an attempt was made to disguise the character of the Pampero and her purpose, and the men were all ordered below. Lopez was delighted to find that his anticipations were wrong, for there were no men of war in the harbor and the barracks were empty. As the Pampero docked, and the men came on deck, they were greeted by a shouting mob of enthusiastic people. They were welcomed as heroes, and the inhabitants came on board bearing food of the most tempting variety and cases of champagne. A feast followed, at which the health of the filibusters and the success of the expedition was drunk with shouts of approval.

Now the expectation had been to go up the St. John's River, where a quantity of artillery for Colonel Crittenden's regiment had been hidden, but the false reports in the forged letters made Lopez anxious to be on his way to Cuba, and it was argued that the artillery would be ineffective in the first engagements, for the roads were very bad, and Lopez hoped to take to the mountains and conduct a sort of guerrilla warfare. The St. John's River was some distance away, and there was always fear of interference from the United States Government; and besides, since this was merely a vanguard for a much greater invasion of Cuba, and was intended to pave the way for the coming forces, why not proceed to the rescue of the Cuban insurgents and let those who would follow bring the artillery? Consequently, after consultation with his officers, Lopez decided to sail for Cuba by the shortest route.

On nine o'clock of the morning of August 11, the filibusters found themselves about ten miles from the harbor of Havana. Off Bahia Honda they took on a pilot. Meanwhile, two vessels were sighted, and were believed to be Spanish ships lying in wait for the expedition. A contest of wits ensued, in which Lopez was victorious, and the Pampero successfully evaded her pursuers. At eight o'clock that night they neared Morillo, and Lopez decided there to make his landing. At eleven o'clock this was accomplished, and while the provisions, arms and ammunition were being brought ashore, the men were given permission to lie down on their arms and rest for two hours. It can be imagined that they were in the highest state of excitement and in no condition to sleep, even if the attacks of mosquitoes had not made this impossible.

Now the information which Captain-General Concha had received concerning the expedition had led him to believe that the landing would be made at Mantua, and he was delighted when information reached him, as it speedily did, that the filibusters had gone ashore at Morillo. He quickly dispatched Colonel Morales by rail to Guanajay, where he collected a Spanish force of about four hundred men, who were instructed to attack from the front; while General Ena from Bahia Honda and Colonel Elezalde from Pinar del Rio were to join forces to cut off retreat, if the filibusters attempted to escape by sea, and thus Concha hoped to surround and destroy the army of invasion.

Meanwhile, the Pampero had been cleared, and under orders from Lopez set out on a return trip to Key West to bring reinforcements, and Lopez decided to march his forces to Las Pozas, ten miles away. Contrary to their expectations, the filibusters had found the town of Morillo practically deserted, and there were no enthusiastic patriots to welcome their would-be deliverers. Now difficulty arose as to transportation of the provisions, and the main portions of the military supplies. There was no practical means of conveying them to Las Pozas, and in consequence Lopez made a mistake which afterward proved his undoing. He concluded to divide his forces, leaving Crittenden, with a hundred and twenty men, to guard the supplies, and himself, with the remainder of his army, to push on to Las Pozas.

He reached this objective without mishap, but again found conditions very different from what he had been led to expect. This town, too, was almost deserted, and there was the same disheartening lack of support, and failure of the Cubans to join his expedition. Lopez determined that on this occasion there should be no occasion to bring against his army the accusations which the Spaniards had made at Matanzas. He therefore ordered his men to accept nothing in the way of food for which they did not pay, and he stationed guards at places where liquor was sold to prevent any drunkenness on the part of his men. In consequence the best of order prevailed.

An attack from the Spaniards was momentarily expected, and Lopez maintained a careful watch for the approach of the enemy. This was delayed until the next morning, when, in spite of his precautions, he was taken virtually by surprise. A portion of his forces were eating their breakfast, while others were bathing in a nearby stream, when word came that the Spanish had overpowered the outposts, were then within two hundred yards of the village, and that the attacking force was estimated to be twelve hundred strong. Lopez hastily issued the call to arms, and his men were arrayed to meet the on-coming Spaniards. A hot battle ensued, in which, in spite of the fact that they were so largely outnumbered, the filibusters were victorious and forced the Spaniards to retire. However, Lopez suffered a very great blow in the death of Colonel Dorman, who was the best disciplinarian and most efficient organizer and drill-master in the army, while Colonel Pragay, Lopez's chief adviser—who, however, had been responsible for persuading Lopez to make the mistake of leaving Crittenden behind—was also killed, as was Captain Overto. The other casualties amounted to fifty killed and wounded. Even the fact that the Spanish losses were far heavier did not compensate for the loss to Lopez of his three brave commanders.

Lopez's army had been increased by only a few stray Cubans, whom they had encountered on their march to Las Pozas, and who had joined fortunes with them. He now had fifty-three less men that at first, and besides he was separated from his stores. Unless they were promptly brought forward, or unless he returned to Morillo and Crittenden, he would be in a serious situation, since help from the natives was not materializing. While he was contemplating this situation, a messenger arrived from Crittenden, asking permission to join Lopez, and the messenger was promptly ordered to return with orders to Crittenden to march his forces to Pinar del Rio to join Lopez there, and Lopez headed his men toward the mountains, with the intention of pushing on to Pinar del Rio.

Promptly on receipt of the desired permission from Lopez, Crittenden, with his one hundred and twenty men, set out to join him. They had proceeded only three miles when the little band was attacked by a body of five hundred Spaniards. Crittenden's men quickly took to cover, and fought so desperately that in spite of the fact that they were so greatly outnumbered, they killed a large number of the Spanish forces, and put the others to rout. But Crittenden, it would seem, had not learned the proper lesson from the earlier division of Lopez's forces, and his own plight in consequence, for he now decided to make the mistake a second time. The little band had made slow progress, because of the necessity for transporting the supplies in carts, and Crittenden made up his mind to leave Captain Kelly for the time with forty men to defend the supplies, and with the remaining eighty himself to lead an attack against the Spaniards who were now rallying. But the Spanish soldiers were better trained than were Crittenden's men, and the Spanish leader was cleverer in manoeuvres and had a greater knowledge of the country. He had no difficulty in effecting a separation between the two bodies of Crittenden's men, and he forced those under Crittenden to flee for their lives. They took refuge in a wooded ravine, where they remained for two days and nights without food and without water, in constant terror of a Spanish attack. Realizing that if they stayed where they were they faced no better fate than slow starvation, they finally, under cover of the night, emerged from their hiding-place and made their way to the coast, where they took possession of four small boats and set out to sea, in the hope of reaching Key West, or of being picked up by some other expedition, since they had no doubt that several were already on their way from the United States. Two days later, starving, and almost mad for want of fresh water, driven by the tides back to the shore and aground on the rocks, they were captured and taken to Havana.

The Spanish General Bustillos, gives the following account of their apprehension: