A/N Thanks to Cerusee. Read the story this was inspired by!

For the 'god for a god' bit, look up How do you kill a God? on Pinterest of google or whatever. It has Aphrodite, Hera, Zeus, Apollo and finally Hades. (Look for L.H.Z How do you kill a God?)

Thanks also to Moffat (one of the duo of Moffat and Gatiss, who most of you will be aware Tumblr has a love/hate relationship with over Sherlock and Doctor Who) who wrote the absolutely cracking Doctor Who episode Heaven Sent which aired all the way back in 2015 (gosh) for the bird diamond mountain bit. It's an amazing episode.

Bruce decided stargazing was something to do more often. Maybe next family night, they could all do this again. Certainly he'd bear it in mind. Nothing felt better than having his children and surrogate father near him, around him, beside him. Jason was as large as him now, and Dick was so grown up...most of the time.

"Bruce?"

Bruce squinted at his eldest son, unable to properly meet Dick's eyes where he was curled around his father's head. "Yes, son?"

"Tell a story, like you used to when I had nightmares. I'm sure you did it for Jay, too," Dick wriggled down to rest on his father's shoulder so he could watch Bruce's face, "so even you should manage not to mess up, emotional minefield that you are and all that." Bruce smiled up at the stars at his son's masterful cracking of the tension grown by the request.

"Alright. Jay, is that okay?" Bruce really didn't want to make his secondborn uncomfortable after they'd got so far. Jason nodded, silent. "Hn, what about..." Bruce smiled slightly and began.

"Once, a very long time ago, the gods walked the Earth alongside humans. It was a time of peace, prosperity, love. The immortals were haughty and aloof- except for one rather plain goddess. She looked weak and insignificant and the only one who feared her was the King of the Gods- her youngest brother- because she shared her colouring with their father, who was a monster. The young king was deeply dissatisfied with this and set out to get rid of her, to make her retreat into the Underworld, even to ensure her death. He was however faced with one glaringly impossible obstacle: how does one kill a god?

He sent out the most beautiful of his court: Aphrodite, the Last Titan. She was to set the question to the humans, whose ingenuity knew no bounds except the indomitable laws of the universe itself-and even then, only sometimes. How does one kill a god?

With fire.

Ice.

Pain, sorrow, grief.

Aphrodite knew those answers wouldn't help her, so she asked others. Old, young, male, female, rich, poor. And she always got the same answers, until one child spoke a great truth: you can't kill a god, because they are eternal. Stunned by this obvious yet unsuspected truth, Aphrodite went to the God of the Underworld, the King of Death and the Dead. To him she offered this tale, and asked what had come to be known as the Great Question: how does one kill a god?

You can't, he said after a long time, because we are eternal, unless you have an eternity. Confused, Aphrodite asked for a bit of clarification. The King smiled humourlessly and explained. Gods each have an eternity. Eternities can be given and rejected but not stolen. A god for a god, an immortal for an immortal, an era for an era. If you want to be mortal, you come to me and give up your eternity. It's painful and you won't get it back; be wise. If one wants to be immortal they must come to me and ask for an eternity, and be judged. If they are judged worthy then they must have a worthy god or goddess to stand for them. If this is acceptable then and only then will I bestow the eternity. There is one who controls the fires of life, who may bestow and take away without needing me, but she respects her abilities and does nothing without reason and worth. As for murder, well, one cannot steal without repercussion. The punishment for stealing an eternity is eternal punishment, and the return of that god's eternity. If a god kills another god...both must die. The price of taking an eternity is giving up your own.

Gods are not exempt from punishment.

Aphrodite swallowed in fear and asked the question she wasn't sure she wanted answered. How long is an eternity?

The King smiled. Ask the children, the mothers, the fathers. Someone knows the answer. Seek and you shall find. Aphrodite didn't know if the smile was cruel, or amused, or something else. The King of Death was unreadable.

Upon reaching the surface Aphrodite collapsed at the nearest well, burying her head in her arms and bursting into tears. This was too much to ask. How? How could she answer this when she would be punished for the answer to the Great Question? It sickened her, now. How does one kill a god? Broken-hearted by the knowledge that she would be judged for the answer and likely abandoned by the Olympic Court Aphrodite screamed into the heavens.

A kind woman who lived near the well heard her, and came out. Hush, child, she said, and come into the warmth. Snow is not a good place to cry. Come in.

Once in the warm house, Aphrodite was wrapped in a soft woollen blanket and given a bowl of stew. The Goddess of Love and Beauty had never felt this much love in a single woman before, and saw that the woman's beauty originated in her purity of spirit. After she'd eaten and been told to get a good night's sleep before telling her story, Aphrodite asked the woman how many children she had. Seven, laughed the woman, though I have borne none myself. Sleep now.

Aphrodite slept.

How long is an eternity?

The kind woman smiled as Aphrodite asked this whilst they cleared breakfast away. Well, she said, I'll tell you a story.

There is a glass mountain. Its heart is of diamond, and the diamond heart would take an hour to climb and an hour to go around. Every one thousand years, a tiny bird- a robin- sharpens his beak on the mountain. When the glass is all gone, he starts on the diamond. Once in every thousand years the robin sharpens his beak, whispering words we cannot understand, and flies away. It takes longer than we can comprehend, but the mountain is worn away. When it is gone, the first second of eternity will have passed. That is why gods can't die, child. An eternity is just too valuable for its theft to be unpunished.

Valuable? asked Aphrodite. Why valuable?

The woman's eyes glinted in the lancing sunlight. Because of what you can achieve when you do it right, and the love that can carry you through anything.

Aphrodite frowned, and the woman left her to think.

So, reasoned Aphrodite, an eternity must be paid for, as all life, because all life is precious, and we can do so much good with an eternity. Okay. Gods cannot die because we would pay with our own lives, and be extinguished, and it's so hard to kill a god I doubt anyone but Hades himself understands exactly how to do it. It's certainly an effective deterrent.

There was one thing left that she did not understand: Why? Why did the robin return to his thankless task? Imagine Aphrodite's surprise when a young voice answered her: the robin did it for love.

Aphrodite yelped, and leapt to her feet. She saw a young child standing in the doorway, and frowned. Love? she asked, and beckoned the child in. What do you mean by that?

Well, reasoned the child who was no more than ten, mum always says that she'd return to the mountain for eternity if it was for us. She says that in the centre of the mountain there was a tiny hollow, and in that hollow was the robin's egg. Mum says that the robin knew that was all he had left of his lady robin, and that he would do anything to get to his egg because he'd loved his lady. She says that a father's love is as strong but less violent than a mother's love. We don't have a dad, but mum would tear apart anyone who tried to hurt us. She says the robin survived eternity because he loved his egg and was determined to have his family again. I think love's the only think that can beat an eternity.

Aphrodite was again stunned. She thought vaguely that she'd been shocked, surprised and confused more in the last few months than ever before. Love? Gods cannot die...but love can triumph over an eternity. I need to think about this, she said, so I'm going for a walk. The child smiled and told her to be back by sundown for the evening meal.

Aphrodite walked for miles, until she came across a temple dedicated to her. Entering, she saw that the only person present was an old, old man. Settling onto the bench beside him, she asked if he would share his wisdom with her on the matter. The old man nodded, and told her to tell her story. She did, pouring it out and venting the pent up emotions she carried. After a long while, she finished, and cried out through her tight throat and messy tears: what does it all mean?

The man was quiet as she panted and drew herself together again. When she had regained her composure the man gently said that perhaps what she should take away from this is a few simple truths: first, gods cannot die unless their killer dies to pay the price; second, that eternity is a very long time indeed; and third, that love makes the eternities borne by gods a lot easier to survive. Maybe, he said, that is what you should tell the King of the Gods. He stroked the hair from Aphrodite's face and said, be strong, for you are one of the goddesses with the most power, and it will be easy for you to lose sight of the truths of the universe. Aphrodite smiled with hope for the first time in months as the man left her in the small temple. Perhaps the woman in the village was right, and anything could be carried by love."

Bruce fell silent, and knew his boys- and girls, for they'd drawn close during his narrative- were thinking this over. He thought on that story a lot when he was down or worried because it reminded him of the strength of his love for his own children, his Robins, his everythings. Pressing his lips to Dick's dark curls, Bruce closed his eyes and thanked God for the gifts of his children just as he knew Alfred did daily. They were quiet and at peace and Bruce wanted it to last forever.