The experiment was not conducted.
It turned out that when the choice was between the Secret Art of Spiritualization and Tsunade's neck, Shizune did not deliberate for long.
The scene had changed entirely by the time this was all resolved. Not the ruined street, not the collapsed building, not the rain-soaked crater where the slug had absorbed Finn's Thunder Bomb. Instead: the interior courtyard of what had been Hanzo of the Salamander's personal residence, now Finn's. A receiving room with low furniture and a proper roof keeping the drizzle out. A tea table. Actual tea, steaming gently in ceramic cups.
Tsunade sat across from Finn with no restraints on her body. No seal tags. No guards stationed at the door. Whatever the circumstances of her being here, the treatment was that of a guest, if a guest who had arrived under somewhat irregular conditions.
Finn was reading.
He sat cross-legged on a cushion with the Secret Art of Spiritualization scroll open across his knees, moving through it with the focused quiet of someone who had no intention of being interrupted. Shizune sat close to Tsunade's side, hands folded in her lap, occasionally glancing at Finn with the particular care of someone who has recently been given excellent reasons to be careful.
Tsunade watched him read her clan's stolen technique for a moment, set that thought aside, and asked, "If you already took what you came for, why are we still here? Why haven't you let us go?"
Finn didn't look up. "I want to point out that I consider this a transaction rather than a taking. Would you agree, Miss Shizune?"
Shizune looked at him, confused. "Why are you asking me?"
"Your professional opinion. As the other party to the exchange."
Shizune opened her mouth, looked at Tsunade, looked back at Finn, and said nothing.
Finn continued, still not raising his head. "I traded Miss Shizune's continued good health for the scroll. The scroll changed hands, you're both still breathing, accounts balanced. That's commerce. Not robbery. Would you call it robbery, Miss Shizune? I'd find that rather unkind."
Shizune felt distinctly that she had been placed in a position with no good exit. She understood she was being used as a rhetorical prop and felt, very specifically, that she would have preferred to be invisible. "Maybe," she said, with the careful tone of someone navigating a narrow path in the dark.
Finn seemed satisfied.
Tsunade looked at Shizune, who sent back a helpless glance. Tsunade gave up on the argument. It wasn't worth the energy.
"Fine," she said. "Call it whatever you want. Transaction, commerce, friendly business arrangement. The scroll is gone. So why are we still sitting here?"
Finn finally turned a page.
"I said it at the start. I have a genuine admiration for you, Lady Tsunade, and I wanted to meet you properly, speak with you directly, take the time to get to know each other a little. If things go well, I'd call that the beginning of a friendship." He spoke with the calm of someone reading aloud from a document he'd already filed in full. "I should mention, while we're on the subject, that I'm on good terms with both your former teammates. Orochimaru is obviously a member of this organization. Jiraiya came all the way out here not long ago to share a drink with me. I declined, but the invitation was there."
Tsunade stared at the top of his head.
He admires me, she thought. This man who trapped me in a mercenary organization's village, coerced the technique out of Shizune's hands under threat of killing me, then picked me up by the throat and dangled me off the ground. He admires me. He wants to be friends.
"So after you forced a deal on us," she said, her voice going precise and flat, "you have the ambition to suggest we should be friends. Is that what I'm hearing?"
"Is it so unreasonable?"
He looked up.
His eyes were direct. Not guarded, not calculated. Whatever he was presenting to her at this moment he was presenting without intermediary, the stated appreciation sitting plainly on the surface where she could look at it or not. It was the gaze of someone who genuinely did not see the contradiction he was being accused of.
Tsunade had been angry a moment ago. She was still, technically, angry. But something about the directness of it caught her off guard, and the anger found itself with less to grip.
She was not a young woman. She had been appreciated, desired, admired, and sometimes feared by people across a career's worth of encounters with powerful men. She knew how to read each of those things and had her own settled opinions about all of them. This was something slightly different from the inventory.
He was not performing for her. He was not angling. He simply looked at her with the particular candor of someone who had evaluated the situation and arrived at a conclusion he found obvious and saw no reason to dress up.
She looked away first, which she noticed and mildly resented.
Shizune, watching from her seat at Tsunade's elbow, felt several things happen internally in quick succession. The first was surprise. The second was a familiar, half-formed concern that she tried to push back down before it developed fully.
She had spent enough years close to Tsunade to read her. Not perfectly, but well enough. And the way Tsunade had just looked away told Shizune something she hadn't expected to observe today.
Kato Dan's death had never fully left Tsunade. Shizune understood that. She'd watched it from the inside, had seen how the grief had transformed over years into something more layered and harder to name, a cultivated fidelity to a memory that had grown gradually more perfect as it grew more distant. The dead never disappoint. They never change. The version of Dan that Tsunade had been holding onto had been polished by time until it was something closer to an ideal than a person.
But Shizune had also watched, quietly, as the quality of that grief had shifted over the past several years. The sharp loss had softened. The absence had become something Tsunade carried without needing to set down regularly and examine. It wasn't gone, but it had moved into the background of her life rather than standing at the front of it.
Shizune's own honest assessment of where things should have gone, if the world had been arranged more fairly, was Jiraiya. He was the obvious answer, had always been the obvious answer, to anyone paying attention from the outside. Persistent, genuinely devoted, willing to absorb Tsunade's worst moods without flinching, and carrying his own obvious feelings with the particular graceless sincerity of someone who had never been good at concealing them. If circumstances had been kinder, if they'd had more time together before everything went wrong, she thought they would have arrived somewhere.
But circumstances hadn't been kinder, and they hadn't had the time, and here they were sitting in a stolen courtyard in the Rain Country across from a man who had manhandled Lady Tsunade through a city block of ruined buildings and was now looking at her with something that Shizune could only reluctantly describe as fondness.
The world was not arranged in ways that made sense.
Finn pulled himself back to the practical. He could read the shape of the room well enough. Tsunade was not going to hate him, which was the thing that had actually mattered. Establishing that she didn't hate him was the necessary first step, and the first step appeared to have been taken.
The second step was clearing the weight of the technique off the table before it calcified into something that permanently soured the relationship.
He closed the scroll, set it aside, and cleared his throat.
"I want to acknowledge that what I did earlier was crude," he said. "The method I used. I came to this knowing that was true. The reason I used it anyway is that the Secret Art of Spiritualization genuinely matters to my work, and I couldn't find a path to this conversation any other way." He paused. "That said, I'd still like this to be a transaction in good faith. I've read through the technique. I have what I came for. In exchange, if there's anything either of you need, anything the Yorozuya can offer, I'd like to honor that. Whatever form that takes."
Tsunade looked at him. His posture was open. The scroll was sitting to the side rather than in his hands. The gesture was what it appeared to be.
She had been in enough negotiations across her life to know when someone was performing humility and when someone was expressing it. The distinction wasn't always obvious, but it was always present.
A man who had her at his mercy, who had taken what he came for and held all the cards in the remaining hand, was sitting across from her and offering to honor a trade anyway. Not because he had to. Because he'd said he would, and apparently that meant something to him.
The realization arrived with a slightly uncomfortable warmth behind it, which she noted and set aside.
She thought about it for a moment.
"I can't think of anything specific right now," she said. "But I'll make it a condition instead. An open promise. If I need something in the future, something I can only call in once, you agree to do it."
Finn considered this. An open promissory note from someone with his resources and connections, held by someone with Tsunade's principles, was not a small thing to hand over. He'd need to honor it, regardless of what it turned out to be.
He thought about Tsunade's character. The way she'd come all the way from the Stone Country without hesitation because she couldn't accept a secondhand account of Orochimaru's death. The way she'd protected Shizune by giving up the scroll rather than the other way around.
He smiled.
"Agreed."
Tsunade's expression shifted slightly, then resolved. She stood, straightening her coat, and looked at Shizune.
"Then there's nothing keeping us here. Shizune, we're leaving."
Shizune was on her feet before Tsunade finished the sentence, piglet tucked under her arm.
Finn watched them move toward the door without moving to stop them. He understood the principle well enough. The moment to push was before the pivot, not after it.
Just as Tsunade's hand found the door frame, he said, "Orochimaru should be finished with his current work before too long, if you'd like to see him. I could let him know you're here."
Tsunade stopped.
The effect was immediate. Whatever complicated, grudging detente had begun to form in the room over the last several minutes encountered the name Orochimaru and combusted cleanly.
"If I see him right now," she said, her voice very controlled, "I will not be responsible for what happens." A beat. "He knew. He knew I would come here if I heard that news, and he handed that information to you anyway. That man."
She pulled the door open and shut it behind her with a force that was precisely not quite a slam, which took more discipline than an actual slam would have.
The sound of her footsteps and Shizune's smaller ones moved away down the hall.
Finn sat in the quiet for a moment, thinking about Orochimaru's expression when he found out what Tsunade had said, and then he started laughing, and couldn't quite stop for a little while.