Vunwulf,
I agree to your conditions. When the Emperor arrives, I will pass along his schedule, and arrange for all doors to be unlocked, and any posted security to be conveniently absent for a small period of time.
Nothing will stand between your men and his eminence. He will die by Stormcloak hands, and neither my father nor your great leader Ulfric will even know anything is amiss until it is too late.
Leave the first payment, in gold, at this dead drop.
I look forward to continuing our relationship.
Gaius Maro