The Doctor stared at her, a look of betrayal that almost had Missy's smirk falter slightly before she managed to pull it back.
"How could you do this, I thought you were getting better, but you let Bill walk onto this ship knowing what would happen." He spoke softly, his voice ringing with the hurt that he was feeling, as well as the guilt for trusting Missy, knowing full well what the consequences of that could be for his human friend. "So, it really all has just been an act this entire time, you're incapable of change!" He spat at her furiously.
It was The Master who got in between them, defending his future self with a gleeful chuckle, "If you ever believed any differently then you are the one to blame Doctor, after all, how long did I keep you in that little cage?"
Nardole was about to interrupt, unsure what he was actually going to say to calm the tension between the two male Time Lord's when Missy pulled her counterpart backwards, slapping him across the chest with the back of her hand.
"If you speak for me again chuckles, we're gonna have to revisit the idea of me making soup out of your organs." She hissed at him warningly, the charismatic sociopath she normally portrayed herself as nowhere to be seen. Instead she was cold and dangerous, no one in the room had any doubts that she was being serious.
"Now Doctor," She drawled, stepping closer, unperturbed when he held up a hand to keep her back, "You listen closely to me now, I. Didn't. Know."
"Lies." He countered immediately, turning away.
She caught his wrist before he could go far, locking eyes with him intensely, "I didn't know, otherwise I would have warned you. What kind of best friend would I be letting your squishy little pets be harmed? I didn't know."
"You put Clara inside a Dalek, I nearly killed her!" The Doctor reminded her immediately.
Giving a long-suffering sigh, she waved her hands at him, "I was teaching you a lesson, and she was fine, I never actually hurt her."
"She told me you hung her upside down and threatened to cook her."
"Doctor." She said, quirking her head to the side and smiling mockingly, "Do you really think I would have ate the loud one, you know I actually quite liked her, but she wouldn't have made a very good meal."
It was then that Nardole decided to jump in, waving his hand between the two of them, "Are you really debating this right now, do you not think you've gone the tiniest bit off topic."
The Master laughed darkly behind them, "I do."
"Creepy, but thank you for at least agreeing with me." Nardole told him reluctantly.
Attention back on The Master, The Doctor glared hatefully, looking between him and Missy before addressing the female version of his best friend. "You're standing right there, how can you really expect me to believe you didn't know this was happening when you have already lived through it?"
Missy waved a hand dismissively, "Knowing the future would change it, whatever happened, or whatever will happen here, he won't be allowed to remember it. It won't surprise me if it ends up being you who erases this whole encounter."
"And so you're telling me there's just chunks of unaccounted for time in your memory and you never went looking for what might belong there?"
"I'm crazy," She reminded him, fluttering her eyelashes, "Do you really think I care?"
"Yes."
Stopping, Missy smiled genuinely at him, "You always did know me best. You're right, I looked, but without a Tardis and with so much else to occupy my time, eventually I just stopped looking, there didn't seem to be any recurring consequences of whatever had happened so it stopped seeming important after a while."
"Well you're finding out now." The Doctor ground out eventually, once he decided whether to believe her, "So what's going to be your next move?" He asked, nodding to The Master, who was watching the entire exchange with interest. "Fall back on a lifetime of bad habits or try and actually do the right thing."
Missy just smirked, before turning and stepping towards The Master, pulling him closer to her and playing with the buttons on his shirt idly.
The Doctor's face fell as he watched not one, but two Master's gearing up to stand against him.
Humming in the back of her throat, Missy considered her old face curiously, having never realised just how much she had disliked needing to shave.
"Without hope." She murmured contemplatively, her old self's face twisting in confusion, as the ever-present insanity dancing in her eyes dulled, and instead she watched him with a sharp intelligence.
Head snapping up, The Doctor was suddenly watching her anxiously, his whole-body tense and unmoving.
"Without witness." She added, a touch louder, dragging her finger along The Master's jawline.
Jamming the handle of her umbrella against the ribs of her past body, she stepped back as he collapsed to the ground, the remnants of the electricity she had knocked him out with crackling in the air, "Without reward." She finished, glancing over at The Doctor, "You may doubt it sometimes, but I am, and always will be your friend."