The restless spirit of the leader carried him on, and within fourteen days of his arrival at the islands he started on a new expedition to Cartagena, casting anchor in that harbor on the 18th of October 1572. A party of horsemen came down to the shore displaying a flag of truce, and met him with fair promises of friendship and assistance. Suspecting treachery, the English put off to sea next morning, but remained for some days in the neighborhood to the great annoyance of the Spaniards, who constantly endeavored, though without success, to induce them to land and thus draw them into an ambuscade. At length falling short of provisions, and seeing no prospect of capturing any valuable prize, they set sail for the gulf of San Blas. On the return voyage, which occupied twenty-five days, they suffered severely. Baffled by contrary gales, their small, leaky craft, in imminent peril from the heavy chopping sea, their provisions exhausted, many almost perishing from want and exposure, they had never lived to rejoin their comrades, but that, in the last extremity they were fortunate enough to capture a Spanish vessel, "which," as the chronicler tells us, "being laden with victuals well powdered and dried, they received as sent them by the mercy of heaven." [Sidenote: THEY CROSS THE ISTHMUS.] Drake remained for several weeks in his lurking place among the islands. At length the welcome news arrived that the Spanish fleet had reached Nombre de Dios, and the adventurers at once began their march overland toward Panamá. Sickness and the bullets of the Spaniards had sorely thinned their ranks. No treasure had been captured, and twenty-eight of their number had already found a grave in this land of promise, among them two brothers of Drake; one through disease, the other while leading a rash attack on a Spanish vessel. Several of the party also lay ill of the 'calenture' fever,[XXIII‑6] caused by the unhealthy climate and unwholesome water. After a slender guard had been left over the ships, but eighteen men could be mustered fit for active service. Thirty cimarrones who accompanied the expedition carried the provisions, leaving the English unencumbered except by their arms.[XXIII‑7] Many days the party journeyed, forcing their way through dense underbrush and cane-brake, crossing swollen streams and toiling up mountain steeps. Yet they suffered little hardship. High overhead a canopy of leaves screened them from the rays of an almost vertical sun. The country abounded in wild fruits, and as night approached the cimarrones erected rain-proof sheds thatched with palmetto and wild plantain leaves, under which they cooked their meal of wild boar's flesh or other forest game, slain during the day's march.[XXIII‑8]