He had observed the direction taken, and thought they could easily surround and cut them off.

He did not think there were more than six in the party; probably they were out hunting, unconscious of the proximity of any foe.
Stark was on his feet in a second.

This was just the chance for the Rangers.

Seizing their arms and hastily conferring together, they laid their plans, and then divided themselves into three companies of three, planning to fetch a circuit, keep under cover, and thus surround the little company, who would believe themselves entirely overmatched, and some of whom would surrender at discretion, if they did not all do so.
Stark, Fritz, and Charles remained together, taking a certain path as agreed upon.

They crept like Indians through the wood.