Please help me to understand how I can fit the last sentence "and worked up the guards into a frenzy" into the whole section.

[mahmoudk]

“Lady Sybille was the wife of Edmund, the Eighth Lord Berkeley, during the time of the Civil War. Edmund wasn’t a nice fellow by all accounts—legend has it he mistreated his wife terribly, and so she secretly plotted against him with one of Cromwell’s spies. One fateful night in 1643, she waited until her husband fell asleep, and stabbed him to death. She attempted to escape the manor, to take secret intelligence to her co-conspirators, but was captured by a royalist patrol. The records state that her white dress was stained entirely red with blood. When they entered Lord Berkeley’s bedroom, they found such a scene of carnage that it resembled a charnel house—as though Sybille had been in the grips of madness when she’d attacked her husband. You can guess, of course, where the bedroom was.”

“The Red Tower,” I muttered.

“There has been more than one historian who questions how Lady Sybille could wreak such havoc alone,” Esther interjected. “And whether she was fleeing the scene of a crime, or fleeing for her life. Ironically, it was only months later that much of the county fell to the parliamentarians anyway, making her situation all the more pointless.”

Crain shrugged. “Edmund Crain had been the highest authority in a region beset by turmoil, and now that responsibility fell to his eldest son—from Edmund’s first marriage, you understand. He condemned Lady Sybille as a traitor and murderess, and worked up the guards into a frenzy.”

 

[5jj]

You need the words following to make sense of this. What happened to Lady Sybille?

 

[mahmoudk]

This is the continuation:

She was given a rudimentary trial—if you can call it that—right then and there, at the scene of the crime. She was found guilty, a noose tied about her neck, and then she was thrown from the tower window. Records on the matter are scant, but local lore says she died slowly, and her body was left out for the crows as a warning to any who might sympathise with her. Indeed, in the days that followed, several servants who had supposedly helped her liaise with the parliamentarian spy were rooted out of the household. Anyway, it is said the red ivy that now clings to the walls began to grow the day Lady Sybille’s body was cut down, and that it continued to grow despite all attempts to cull it.”

 

[5jj]

She was given a rudimentary trial—if you can call it that—right then and there, at the scene of the crime. She was found guilty, a noose tied about her neck, and then she was thrown from the tower window. Records on the matter are scant, but local lore says she died slowly, and her body was left out for the crows as a warning to any who might sympathise with her

That is the result of the guards being worked up into a frenzy.

 

[Barque]

If you're asking about the grammar of the sentence, you can read it like this: He condemned Lady Sybille as a traitor and murderess, and [by doing so, or along with doing so, he] worked up the guards into a frenzy.