He found willing instruments in the persons of Webster and Spencer, two adventurers of daring character and questionable antecedents. Webster drew up a plan of operations which met the approval of Vanderbilt, and Spencer was entrusted with its execution. This Spencer was a man of good family. His father had been Secretary of War. His brother was hanged for mutiny at the yard-arm of the brig-of-war _Somers_ in 1842, the only American officer who ever achieved that infamy. Spencer went to San Jose, the capital of Costa Rica, whence he set out, with one hundred and twenty picked men, for the head waters of the River San Carlos, which flows into the San Juan. Arrived there, they constructed rafts and floated down to the mouth of the Serapiqui. There they surprised a force of Americans, and continuing the descent to San Juan del Norte, soon made themselves masters of the Transit Company's steamers. With them and a reinforcement of eight hundred Costa Ricans, commanded by a brother of President Mora, they speedily captured all the fortified positions on the river and both of the lake steamers. Lake and river being thus secured, it only remained for Mora to cross the district of Chontales and effect a junction with the Allies at Granada. The enemy had effectually cut off Walker's communication with the Atlantic States. California remained open to him just so long as the agents of the line in San Francisco, whose friendship for him was, of course, secondary to their self-interest, should consider it profitable to continue running their steamers. Vanderbilt had triumphed. We may anticipate events so far as to say that President Mora's indebtedness to the Wall Street magnate taught him respect for the absolute power of money. But ere many years his confidence in another rich friend was repaid by treachery, which drove him from power into exile, disgrace, and death. Eighteen days after the execution of Walker at Trujillo, Juan Rafael Mora and General Cañas perished by the fusilade, after an abortive attempt to regain their lost power. It is recorded of the wealthy ingrate who had betrayed Mora that he died not long after his victim, and of a strange disease--ossification of the heart.