Tegan is used to nightmares. But she believes there are worse things than violent visions of reptilian monsters. For example, awkward dreams.
When Marriner appears in her sleep, with his serious face and hopeful expression, she has to stop herself from saying "Oh no, you've come to bother me again."
She's not obliged to hold back, since it's a dream. Except that... do you know when you are dreaming? Usually not. Rabbits! It means it's probably a questionable idea to offend a being with godlike powers.
"Tegan," he whispers, bowing before her, always exquisitely polite. She would certainly like these manners from a human suitor, but the suspicion that he took the idea from her adolescent daydreams spoils pretty much all the good in it. "May I talk to you?"
She shrugs. "Why not? Say what you want, and it'll be finished at last."
"You know what I want." Yet he doesn't need insisting to repeat, on one knee. "I want your mind. Please."
It's so absurd and wrong and ridiculous that it could almost be touching. She could point sarcastically that he's supposed to be a godly thing, and get prayers, not to mention steal the energy from them. But it's too much of a sensitive point.
"I'm the last person you should ask," she snarls. "I've already been possessed, and I loathed every second of it !"
He seems surprised at first, but doesn't object at all, just murmuring "You're really like no one else." Of course, he could believe the most incredible truths; he knows everything she thinks. Which, even if it can have its practical, or even nice sides, is globally a nightmare, Tegan's sticking to it.
Marriner's face is still confused, though, when he protests his intentions, like a gentleman charged of shameful motives. "No! It's not like this! I love your mind so much, I wouldn't erase or lessen the slightest thought! Or else it would already be done! I like when you're happy!"
"Too bad. Because it's more likely to happen when you're not near me."
"But we would be the same person, Tegan. Your feelings and dreams and desires, our minds linked, with my powers! You'd be my light, I'd be your strength."
She's not even tempted. Absolutely not. Anyway, how could someone keep feelings and dreams, with immortality and all these powers ? He'd be able to trample on them without even noticing. Thinking about it, maybe it could be the only reason to forgive him his insensibility, and even being such an oaf. Maybe it's an unavoidable consequences of what they are.
Except that, it she was to forgive him, she could pity him, and she doesn't need this at all.
So she resorts to sarcasm again : "Eternity must be a pathetic place, if its inhabitants can desire so much the body of a girl. Don't worry, you'll find better responses to your so tempting proposals elsewhere."
He still doesn't answer to mockery, though it would make things so much simpler, if he got angry! "You're mistaken. I want no one else. Eternity would be wonderful without the memory of you."
"So, you discovered how is it when things come to an end, good. Welcome to the human world!"
"It's the end of something indeed. I see you now for the last time, Tegan. The White Guardian only gave me this night, for the help I gave you, and I am nor permitted to interfere in the physical world."
Has she seen him so sad before? She doesn't think so. Eh, she shouldn't have compassion left for immortal beings; some need it more. Some who died before Marriner, without him showing a sign of regret. He cheats, if he begins to be vulnerable too! How will she keep him a grudge, then?
She even asked the Doctor, who said nothing could be done! Also, her mind is hers alone! There is no other way, so she has no reason to feel guilty, especially since he doesn't reproach her for anything. Oh, how infuriating he can be!
"Too bad for you!" she says, but she has no anger or joy left in her voice.
He kisses her hand "Farewell, Tegan. Your words were harsh, but your thoughts were sweet, and your pride to be yourself burns like a bonfire. I have no regrets."
She could say the same. She's just not sure she could think it hard enough.