The Spaniards soon landed and, taking possession of St. Simon, set out to attack Frederica. But they found it no easy matter, for the town was surrounded by dense and pathless woods. And struggling through them the Spaniards stumbled into marshes, or got entangled in the dense undergrowth until in their weariness they declared that not the Evil One himself could force a passage through. Added to their other difficulties they were constantly harassed by scouting parties of wild Indians, and almost as wild Highlanders, sent out from Frederica by Oglethorpe. But meanwhile no help appeared, and at length Oglethorpe, having discovered that the Spanish force was divided, decided to make a sortie and surprise one part of it. So with three hundred chosen men he marched out one dark night, and stole silently through the woods until he had almost reached the enemy's camp. Then suddenly a Frenchman who was with the little British force discharged his musket, and fled towards the Spanish camp. All hope of a surprise was at an end, and Oglethorpe returned hastily to the fort. But that the surprise had failed was not the worst. It was certain that the deserter would tell the Spaniards how weak the British were, and that thus heartened they would soon attack in force. Something, Oglethorpe decided, must be done to prevent that. So he wrote a letter in French addressing it to the French deserter. This letter was written as if coming from a friend. It begged the Frenchman to tell the Spaniards that Frederica was in an utterly defenseless state, and to bring them on to an attack. Or if he could not persuade them to attack at least he must persuade them to remain three days longer at Fort Simon. For within that time two thousand men would arrive from Carolina and six British ships of war "which he doubted not would be able to give a good account of themselves to the Spanish invaders." Above all things the writer bade the Frenchman beware of saying anything about Admiral Vernon, the British admiral who was coming against St. Augustine. He ended by assuring him that the British King would not forget such good services, and that he should be richly rewarded. This letter Oglethorpe gave to one of the Spanish prisoners they had taken, who for a small sum of money and his liberty, promised to deliver it to the French deserter. But instead of doing that he gave it, as Oglethorpe had expected he would, to the leader of the Spanish army.