Missy couldn't refuse an offer like that. She nodded slowly with a smile, and the Doctor walked towards her. "Every queen needs a king".
"Good, because..." he started, then looked at River, who was kneeling on the floor cradling her arm. With eyes of fire, he rested the sceptre point on the back of her head and with a terrible voice spoke. "Any last words Ms. Song?"
She lifted her head far enough up for Missy to see the terror in her eyes, behind the engineered fearlessness and brutality. "Don't let him see the damage", she whispered in a mouse-like voice. And with a flash of yellow and purple light, she was but a pile of red-stained ashes, with her twisted golden bracelet lying mournfully on top.
"...it seems the job has become free".
Missy breathed heavily and the Doctor planted a kiss on her cheek.
"I will help, but on one condition", she exclaimed.
"Anything, dear. You are my equal".
"I get to keep some of the humans. You know, I might need target practice".
"Which ones?"
"Tom Bateman, Benedict Cumberbatch, Patrick Stump, Channing Tatum, Tom Hiddleston, and Andy Hurley".
"Fine". He opened the TARDIS doors again to see the Earth one last time. He lifted the sceptre in front of him, ready to destroy.
"Can I do it? Fire the sceptre I mean", Missy interrupted, standing next to him. He snuffed, a little disappointed, but eventually gave into her persuasive blue eyes and handed it over. She stepped back to a minute, and with a determined smile pushed the Doctor from the doorway into the inky blackness below. Missy didn't bother looking at him fall, it would only be sentimental.
"Oh, but don't you know Doctor", she murmured with a twinkle in her eye. "This queen doesn't need her king to rule".