Suppose there is a guard working for a minor lord, a castle lord maybe baron, let's call him Robert. He has no personal attachment to either his immediate lord, the count above him, or the king (I mean, not too many people meet their king anyways).
He then gets a letter from the count, let's call him Geoffrey. It contains evidence that Robert is planning a rebellion against Count Geoffrey and has identified a dozen conspirators, including some unlanded sons of nobles and two other barons. The guard thinks about the activity and documents he might have seen around the castle and realizes Robert had been conspiring to rebel for three years and was spending time trying to secure loyalties and formant descent against Count Geoffrey.
The letter asks for the guard, who is assigned to the gatehouse, to bribe the others to keep the thing open with the money contained with the letter. Robert is not yet in open rebellion, so the main gate is usually open (like it is during peacetime) and Count Geoffrey plans to personally come over with his knights and nip the rebellion in the bug. It promises rewards for the guard if he cooperates and also trys to appeal to the guard through legal means (I mean Robert is about to rebel, that's a good reason). Geoffrey doesn't realize the guard also knows Geoffrey lacks any siege equipment and has almost no hope of taking the castle with the gate closed.
The letter later gets wet that day and becomes completely illegible, but the guard knows what was in it.
What is the likelihood that the guard will cooperate and betray his castle lord, and the likelihood he'll simply pocket the money? Even if Geoffrey puts down the rebellion when it happens, he won't even know if the letter got intercepted or reached its intended recipient, so treachery is unlikely to be discovered.
He then gets a letter from the count, let's call him Geoffrey. It contains evidence that Robert is planning a rebellion against Count Geoffrey and has identified a dozen conspirators, including some unlanded sons of nobles and two other barons. The guard thinks about the activity and documents he might have seen around the castle and realizes Robert had been conspiring to rebel for three years and was spending time trying to secure loyalties and formant descent against Count Geoffrey.
The letter asks for the guard, who is assigned to the gatehouse, to bribe the others to keep the thing open with the money contained with the letter. Robert is not yet in open rebellion, so the main gate is usually open (like it is during peacetime) and Count Geoffrey plans to personally come over with his knights and nip the rebellion in the bug. It promises rewards for the guard if he cooperates and also trys to appeal to the guard through legal means (I mean Robert is about to rebel, that's a good reason). Geoffrey doesn't realize the guard also knows Geoffrey lacks any siege equipment and has almost no hope of taking the castle with the gate closed.
The letter later gets wet that day and becomes completely illegible, but the guard knows what was in it.
What is the likelihood that the guard will cooperate and betray his castle lord, and the likelihood he'll simply pocket the money? Even if Geoffrey puts down the rebellion when it happens, he won't even know if the letter got intercepted or reached its intended recipient, so treachery is unlikely to be discovered.