Believing that the farther success of their enterprize depended on the diligence they should exert in reaching Nombre de Dios to surprize the president, before he might have time to embark or prepare for his defence, they determined to proceed to that place without delay. For this purpose, it was arranged that Ferdinand de Contreras should march to Nombre de Dios with the greater part of the troops, while Juan de Bermejo was to take post with an hundred men on a height near Panama, to protect the rear of Ferdinand, to prevent pursuit, to be in readiness to receive the valuable booty they expected, and to intercept such of the attendants on the president as might escape in that direction from Nombre de Dios. In the mean time, Pedro de Contreras was to remain on board with a small number of men to protect the ships. All this was done accordingly; but matters turned out in quite a different manner from their expectations. Marchena got some information respecting their plan of operations, and sent off two confidential intelligent negroes to give notice to the president of what had occurred in Panama, and of the ulterior designs of the Contreras. One of these negroes was directed to travel the whole way by land, and the other to go by way of the small river Chagre, which route had been taken by the president.
This river has its source in the mountains between Panama and Nombre de Dios. Its course at first seems tending towards the Pacific Ocean; but it suddenly makes a turn at a cataract, and after a farther run of fourteen leagues it falls into the Atlantic; so that by means of a canal only five leagues in length, from that river to the South Sea, a navigation might be easily established between the two seas. It is true that it would be necessary to cut this canal through mountains, and in a country exceedingly uneven and full of rocks, so that the design has hitherto appeared impracticable. Hence, in going from Panama to Nombre de Dios by the river Chagre, it is necessary to travel by land in the first place to that river