A single star shone in the night sky. It was a big star, old and angry-red. Around it space was cold and black and time was getting tired.
It had already absorbed most of its original complement of planets, and now it was orbited by a single ball of rock, once cold and now pleasantly warm.
On the last planet in the universe, the Doctor, Jamie and Zoe walked along the dry bed of an ancient sea.
The heat-death of the universe was not what most people would consider romantic, and for once 'most people' included the Doctor. He walked ahead of his companions carrying a blue plastic bag and wearing a pair of sunglasses. He had a purpose.
The best thing about the end of the universe, or, alternatively, the only good thing about the end of the universe, was that all your relatives were safely dead and there was no one around to stop you doing things that you probably shouldn't do.
"Are we there yet?" asked Zoe.
"Just over this hill," said the Doctor, pausing to wipe his brow with his handkerchief.
They reached the top of the hill and then marched down holding hands to avoid tripping over rocks and because they tended to do that sort of thing anyway.
"Right," said the Doctor, confidently, "this is magnetic north." He took off his sunglasses.
Jamie and Zoe weren't entirely sure how he could tell, but they were a bit tired after all the walking and thus prepared to believe him.
"Magnetic north," he repeated, "at the very centre of the Heart-Shaped Galaxy. Or what used to be the Heart-Shaped Galaxy. That's almost certainly the most romantic spot in the universe. Or at least it was, a long time ago."
"If you're sure," said Jamie, who had his own ideas about romance and they didn't involve everyone he'd ever met having been dead for billions of years.
"Now, Jamie, I'd like to ask you something and I want you to think carefully before you answer."
"Are you sure you don't want to ask Zoe?"
"No, not this time, Jamie, this is a question only you can answer." The Doctor looked serious and only slightly terrified.
"Okay," said Jamie, not quite knowing what to expect but willing to think carefully if that was what was needed.
The Doctor got down on one knee, tied his shoelaces, then stood up again. He cleared his throat. "Jamie, will you marry me?"
Jamie thought about it carefully, because the Doctor had told him to. He thought about commitment and responsibility, and about the Doctor's handsome eyebrows. He wondered what his parents would say if they ever found out that he had married a man and an alien one at that.
"Aye, if that's what you want."
The Doctor breathed a sigh of relief. "Good. I was rather worried that you might turn me down."
"I didn't think you were the marrying kind," said Jamie.
"I'm not, really," said the Doctor. He reached into his plastic bag, removed a strip of cloth, and shoved the empty bag back into his pocket to recycle later (somewhat unnecessary when the universe was about to end, but it was the principle of the thing). "Now," he said, "traditionally this should be a strip from my mother's wedding-gown or something of equal sentimental value."
"What is it?" asked Zoe.
"A bit of cloth that I tore a bit off a sheet this morning. It'll do," he added, defensively. He wound one end of the cloth around his hand and gave the other end to Jamie, gesturing that he should do the same.
"Right," said the Doctor, "I don't think we need anyone else's permission for this, so I'm going to tell you my name and I want you to promise never to tell anyone else what I said."
Jamie nodded and the Doctor whispered his real name in Jamie's ear.
Zoe threw some sand at them. They turned as one to stare at her.
"Sorry," she said, "I didn't have any confetti."
"That's perfectly alright," said the Doctor, brushing sand off his coat-sleeves.
"Aren't you going to kiss him?" she asked.
"Yes, of course I am."
"Well?"
Sometimes the Doctor suspected that Zoe wrote homoerotic fanfiction in her spare time. He leaned towards Jamie and kissed him rather chastely on the lips. "There," he said to his new husband, "that should keep you going until the honeymoon."
"I hope we don't have to stay here for that," said Jamie. "It's a wee bit depressing here, romance aside."
"Yes," agreed the Doctor, "it is a bit. Let's go back to the TARDIS, shall we?" He took Jamie's hand and, after a moment's thought, took Zoe's hand as well. It wouldn't do to play favourites even if Zoe wasn't the love of his current life. They headed back to the TARDIS and arrived in time for tea.
A few days later the star that sat where the Heart-Shaped Galaxy had once been began to shrivel and shrink. The universe slowly reached it's end like a string of ellipses at the end of a particularly long sentence. Some might have hoped that something else would happen after that, but those people were far too optimistic and had silly romantic notions about these things. The love of a Time Lord and a human being meant, after all, almost nothing in the grand scheme of things.
But it did mean that the universe ended on quite a big bang.