As Robin bound Isabella's wrists with rope, he couldn't help remembering the time he'd tied up Marian, the day they'd been trapped in a tree trying to bring down the pigeon Lardner.
The memory was bittersweet. It was the day he'd proposed to her, and she had said "yes." But it was also the day she had left the forest and returned to Gisbourne, to save Robin's life.
Marian! Just thinking of her made his heart swell with warmth and love and longing. She was his wife, his love, the mother of his children, yet so much more than that. Words could not describe the depth of his feelings. He adored everything about her, even when she disagreed with him and they argued. Everything about her...everything fit with him. If was as if she had been made for him, yet there were times he felt he didn't deserve her.
His conscience smote him whenever something reminded him of the killing he'd done in the Holy Land, and he felt unworthy to be Marian's husband. He had been following orders, but killing was killing, and he hated himself for being a killer. He tried to put such thoughts out of his mind and strive to be a good man, and Marian's love and faith in him helped him every day to be better. But now, with Isabella's reemergence in his life, he was reminded of his shame and guilt for his sordid relationship with her, the sister of his enemy.
He'd tried so hard to resurrect Marian in Isabella, when he was grieving his wife's death. Isabella had fostered the illusion, learning all she could about Marian and trying to be her, until she fell so hard for Robin she wanted him to only want herself, insisting, "I'm not her!" By that stage, Robin had already pulled far away from her, knowing his feelings were nothing but an illusion, and that Isabella was nothing like Marian, even though he didn't yet suspect the level of her treachery. The few physical encounters he'd had with her left him feeling guilty and ashamed, with nothing of the love he'd experienced with Marian.
He felt guilty now, with Isabella reminding him of an act that shamed him. He hadn't asked for or expected it, and he should have stopped her, but he hadn't. He had never told anyone, least of all Marian, and he didn't want her to know. He wouldn't put it past Isabella to boast of it before his wife, but that was nothing compared to what she had just done to his precious little girls.
Anger toward her washed over him again, as he and Will led her to Nottingham to face Sheriff Wilfred. Isabella was surprisingly compliant, making Will and Robin suspicious.
"Really, Robin," Isabella said, on the way to the castle, "you're no fun anymore, since you got your lands back. I remember when you used to be so cocky, if you catch my double meaning."
"Shut up," Robin furiously ordered, a vicious scowl on his face.
"I only mean how you used to gloat and snicker, once we became enemies," Isabella explained. "Now you're just angry."
"You tried to kill his daughter!" Will shouted.
"Nonsense. I only gave her a present. Was it my fault she put it in her mouth?"
"You knew she would," Robin snarled.
"How should I? I've never had a child."
"Stop playing innocent, Isabella."
"Oh, I'm not innocent. You know that better than anyone, don't you, Robin?"
"I doubt it," Robin said. "There must be a legion of men who know you, Prince John among them."
"Jealous?" Isabella asked.
She was finally rewarded by him snickering, though it was more angry than smugly satisfied.
Will's face face remained blank, his manner determined. He was loyal to Robin no matter what, and no insinuation Isabella could make would shake his loyalty. He hadn't witnessed the brief time Robin had dallied with Isabella, living at the time in Acre, but he knew about it and he did not judge.
Arriving at last in Nottingham, the trio were shown into Sheriff Wilfred's presence.
The sheriff was a fair man, dry and unimaginative, the complete opposite of Sheriff Vasey. He knew the law backwards and forwards, and followed it to the letter. He was also unemotional, and Robin was taken by surprise when he saw the middle aged, married man's eyes light up when he looked at Isabella.
"Good morning, my lord sheriff," Isabella said. "What a pleasure to see you again!"
"What is the meaning of this, Locksley?" the sheriff demanded to know. "Why are the sister's wrists bound? Untie her at once!"
"She is not a sister," Robin explained, "but my prisoner. She disguised herself as a nun, drugged Sister Mary Claire, and tried to choke my younger daughter. I ask for justice."
"Choke your daughter?" The sheriff sounded incredulous. "Do you mean to say, she put her hands, or something else around the Lady Grace's neck? And you're wrong, Locksley. She is a nun. I know her well."
"You know her?" Robin was surprised.
"I do charitable works here in Nottingham," Isabella told him, under a pretense of kindness. "Just as you used to, when you were Robin Hood. Of course, the money I give out doesn't come from robbery." Turning to the sheriff, she explained, "My lord sheriff, this is all a terrible mistake. Sister Mary Claire and I were helping at the mass this morning in Locksley, watching his daughters who couldn't sit still during the service. Sister Mary Claire fell asleep, being elderly, and Lord Locksley claims I drugged her! And as for choking his lordship's baby...I made a mistake by giving her a toy a bit small, which she put in her mouth and choked on. The little darling is alright now, having spit out the toy."
"This is absurd," Sheriff Wilfred said.
"Yes, it is," Robin angrily agreed. "Absurd for you to believe her lies."
The sheriff looked from angry Lord Locksley to impassive Will Scarlett to the beautiful sister, and made a decision. "I order Sister Marian Isabella released," he commanded.
The name he used further outraged both Robin and Will. "Marian Isabella?" Robin cried out to Isabella.
A guard had just cut the binding off her wrists. Facing Robin, Isabella's face still wore a lofty look, but there was a wicked gleam of satisfaction in her eyes. "Sister Marian Isabella," she corrected, "the name I selected when I made my vows to become a bride of Christ. 'Marian,' as in being like our blessed Virgin Mother, and 'Isabella,' my given name."
"You know that's my wife's name," Robin shouted.
"Lady Locksley? Yes, I am aware her name is Marian."
"Marian Isabella," Robin insisted. "It's the full name she was christened."
"What a coincidence," Isabella smirked.
Robin made another plea to the sheriff, who waved him aside.
"Come on, Robin," Will said, knowing that Isabella had blinded the sheriff. "Forget it for today. Let's go home."
"This isn't over, Isabella," Robin warned.
After he and Will departed, Isabella quietly said to herself, "You don't know how right you are, Robin Hood."
...
(Note: Marian's name in the series was indeed "Marian Isabella." You can hear the priest who's beginning to marry her to Gisbourne during the final episode to Season One use that name. And I think he calls Guy , "Guy Crispin Gisbourne," or was it "Guy Christian"? Please correct me if I'm wrong).