The green door.

The green door led to a maze of corridors, twisting this way and that, doubling back on themselves in a way that Amy strongly suspected was non-Euclidean. Whatever that meant. She'd never quite figured it out. She tiptoed through the corridors, arms folded against her exposed breasts and crotch, hiding behind pot plants and antique desks, painfully aware that she was still stark naked and soaking wet. She had a prickling feeling in the back of her neck, like she wasn't alone.

Footsteps, tramping down the corridors. She couldn't be caught! She threw herself behind a Ming vase, just seconds before a Roman legionnaire came tramping around the corner. Amy cowered in her hiding place, her heart pounding, as he tromped by, his armour rattling with each step. What if he'd caught her? Nude in front of a Roman legionnaire! It didn't bear thinking about! And what if he wanted to... to have sex with her? Awful! She had to find a way out of this, and fast!

But she had no idea where to go. She poked her head out. The coast was clear, at least. She darted round another corner and crashed into a handsome, annoyed-looking blonde, who rolled her eyes at the sight of Amy.

"Another one of you?" she said. "TARDIS doesn't like anyone very much, does she?"

"Eek!"

"Alright, stand up. Stand. Hands on your head. There's a good girl."

"I can't... ow! Let go of my ear!"

"No. Stand. There." The blonde had pulled a curious-looking instrument out of her pocket and was running it up and down Amy's body. The redhead stood to attention with her hands on her head, squirming slightly, her whole body exposed for the other woman's inspection. Her cheeks were very red. Whenever she tried to move, the blonde tweaked her nipple until she stopped.

"Very interesting," she said, finally, switching off the instrument. "Your gymnotemporal signature's off the charts. TARDIS must really have a problem with you. Did you make fun of her?"

"Um..."

"You did, didn't you? Foolish mistake. Well now, girl. My name's Romana, and you're coming with me."