Missy shivered as her room aboard the TARDIS seemed to suddenly become freezing cold. She would have to talk to the Doctor about keeping his ship's temperatures level so that she wouldn't end up as a time lady popsicle.
After a while of trying to fight off the chill, she eventually gave up, and got out of bed, huffing as she did. She pulled a blanket around herself, and began making her way to the Doctor's room, her satin nightgown swishing all the way.
When Missy finally reached his room, she slowly pushed open the door and entered as quietly as she could. The Doctor stirred slightly as the door clicked closed, and she froze for a moment, afraid she had woken him. When he remained silent for a few moments, the Time Lady continued her journey to the bed.
As the Mistress moved forward, she contemplated how calm the Doctor looked, asleep. Calm and innocent. She held her breath and began lifting the covers quietly, half hoping that he would wake up and maybe- just maybe- cuddle her and hold her in his strong, yet tender arms. She slipped under the bed sheets and wrapped the blankets around her, tugging them slightly.
She settled in, her head on the pillow and her breathing steadying. Suddenly she gasped as she felt the Doctor's arms wrap around her. The shock initially wore off, and she settled into the Doctor's warmth. "How long were you awake?" She asked, with a tone between annoyed, amused, and relief that he wasn't angry that she was here.
"Long enough to realize that I had gotten the most attractive Time Lady in my bed." The Doctor replied with a small, tired smirk, "not like THAT, of course, but you know."
The Mistress huffed, but in all honesty, she was glad of the compliment, however lewd it had seemed at first. "Whatever, you." She said, "Hold me, I'm cold."
The Time lord smiled, and complied, wrapping his arms around her more and pulling her closer.
They settled together in a spooning position, the two Gallifreyans fitting perfectly with each other. Whatever Missy had created was not heaven, she had realized. In fact, far from it. This.
This was heaven.