Jarvie protests Morris’s death as cold-blooded murder. When Helen asks him if he is not afraid to follow, Jarvie replies that, sooner than proclaim Morris’s death as lawful execution and in spite of the relationship between himself and Rob Roy, he would die alongside Morris than testify that murder was not murder. Helen is seemingly impressed with Jarvie’s courage, and says no more to him.

Helen then asks Frank if he is Rashleigh Osbaldistone, which Frank denies, but explains that they are kinsmen, but not friends. He explains about their recent duel, which Rob Roy had stopped. Helen tells him that he is then trustworthy enough to take a message to the soldiers. Frank then tells her that he, along with his companions, have come into this country at her husband’s invitation. Helen then gives him the message: if they harm Rob Roy, they will destroy the countryside. Jarvie remains under Dougal’s surveillance.

Frank and Andrew are then led by the elder son of Rob Roy to the hideout. Frank is presented to the Duke. Franks gives the message, but the Duke states that Rob Roy must die. The Duke then receives a message that their allies have made a separate peace with the enemy. The Duke then proposes a retreat, but first calls forth Rob Roy. After a short exchange, the Duke allows Roy to send his wife a message.