The Doctor is entirely capable of observation. The subtleties of human relationships might escape him sometimes, but in this universe subtlety doesn't seem to be widely embraced.
The atmosphere here tastes of brutality and smells of fear, and neither of those things have ever been particularly hard to decipher.
It's not like his universe at all.
She is the first shock - this Elizabeth Shaw who speaks like his Liz, moves like his Liz and yet is so repellently not his Liz at all. There's hatred in her heart, twisted in so deep that no glimmer of compassion remains.
He would be a fool to trust her.
She comes down to his cell, boots clicking on the stone floor, and takes the keys from the guard before dismissing him. The cell door creaks as she opens it and locks it behind her.
If he looks at her from the corner of his eye she looks so much like the Liz he knows that he feels oddly unsettled.
"Tell me who sent you," she demands without preamble.
"I've already told you that nobody sent me."
She rolls her eyes and moves to stand in front of him. It doesn't bother her that he could conceivably strike her down with one blow; it's possible that it doesn't even cross her arrogant mind.
Her closeness is unnerving.
"Tell me," she repeats. Her hand runs up his chest to curl around his shoulder and he doesn't dare to shove her away.
He's had a taste of the punishment on this world and it's an experience he's rather not repeat.
So he doesn't push her away, not now, not while he can still bear the feel of her so close to him.
It's harder than it should be to separate her from the real Liz and it feels like a violation of his friend's body to have her behave in this way. It's meant to intimidate him, he knows, and it's working for the simple reason that he knows her face, her voice, her figure, so well.
He doesn't know if he'll be able to face his inquisitive assistant again if he comes to know much more than that.
Elizabeth - because that's who she is, not Liz - smiles triumphantly at what must be a look of horror on his face.
"You say you know me," she says in a low voice. "You don't, but I think I've found your weakness. This body, this face, it disturbs you, doesn't it?"
He doesn't need to reply: the answer is written indelibly in his eyes.
Elizabeth kisses him, biting at his lower lip hard enough to draw blood.
This is when he should push her away, but before he can recover she's pulled back with a satisfied smirk, her hands going to the buttons on her blouse. One eyebrow raises in that challenging, familiar way.
"Stop it," he says.
This universe is wrong on so many levels.
"Tell me who sent you."
"I've already-" It's pointless repeating himself, he knows, but he has to try. "I came here by accident from an alternate universe," he tells her clearly.
"Come, come, I know enough physics to know that's impossible." Her fingers are slowly undoing buttons and he looks away, overwhelmed by the feeling of wrongness. He's not human but he knows how they perceive things and he's sure that his Liz has never worn her short skirt and boots in such a suggestive way.
She takes a breath to speak and the prison door opens in a dissonant counterpoint.
"Section Leader Shaw?"
The Doctor closes his eyes and lets the ridiculousness of it all assault his senses.
"Brigade Leader," says Elizabeth. "I am interrogating the prisoner."
"Your presence is required in my office." He hears the smirk, and Elizabeth's sigh, and he dares to open his eyes. The Brigade Leader is standing in the doorway watching Elizabeth watching him, and with a flash of unwanted insight he knows precisely why he wants her in his office. The same insight tells him that it's vicious and emotionless, a mutual using of each others' bodies, soulless like so much of this world.
She doesn't even bother to do up her blouse.
The lock clicks back in to place behind her and the Doctor sits on the hard pallet bed in the corner of his cell, head in hands, still tasting his own blood in his mouth.
He feels tainted by this place.
When he finally returns to the correct universe he can't bring himself to meet Liz's eyes. However much she smiles and unleashes her wit on him and is generally brilliant, he can't help but remember the feel of that other Elizabeth's body against his or the metallic taste of blood left behind by her kiss. And every time he walks in to a room to find her alone with the Brigadier he can't help but remember the sordid prostitution of another couple in another universe.
She notices his coldness.
He wonders if he'll drive her away, eventually.