You disguise your troops in Henslow's ragged militia uniforms and ride to Dennod. (DM rolls 1d6: 1!) You reach the town gates at twilight. A lone carpenter is setting up a series of ill-constructed tents. You recognize your old ally Prismaticus, almost unrecognizable under a giant hood. "Mearls!" he says. "Look at me, reduced to working for a living, AND for a traitor. Is it time to strike against the Duke?"
"Yes, let's remove the head from the serpent. Do you have intelligence about when we could smuggle him out?"
"Yes, let's remove the head from the serpent. Do you have intelligence about when we could dispatch him?"
"Yes, let's remove the head from the serpent. Do you have intelligence about when we could cut off his serpent?"
(DM rolls 1d20+3: 5!) "We're with you," says Anna, "but the Duke appointed many of the barons up here, and the common people don't care much who's king. The Duke could field 50 soldiers tomorrow and 500 in a month. Of course, if the King is really riding to Dennod right now, it could all be over in a few days, one way or another."
Thank Anna and take our leave. Turn to my group and say "I think more direct action is called for. If the Duke is mustering forces then he will not know all of the soldiers in his camp. Let us infiltrate with the goal of kidnapping him. Without the head, the insurrection will fade away."
Swift action is needed. If we can catch the Duke between our force and the King's before the Duke can raise troops we may have a chance. We have to be careful infiltrating because Lord Hesperus may recognize us.
Rally the countryside to the King's cause and hurry to reinforce the Princess. The Duke will be caught between the hammer and the anvil, as he lays siege to Redrill and the King falls upon him from behind.
Switch sides to join the Duke
I'm gonna need a magic ring and at least four hobbits.