Jack had a daughter. A grandson. A tiny bit of information shared in a moment of heated irritation, before the hero stormed out to rescue his family.
Everything was changing.
Ianto had been in such a profound state of shocked stupefaction that he barely noticed when the secret slipped from his tongue when Gwen asked what was wrong- only enough to be jolted out of it, an intense feeling of guilt bubbling in his stomach.
Then it hit him sideways, suddenly, a rush of affection and hope, love so deep and overwhelming he lost his breath.
Everything was changing, and even with the horrific things still lurking outside, screaming at the back of his mind, all he could think about was him and Jack, and how they would be just fine- better than fine.
He only had a lifetime but it was going to be a lifetime worth living, and he was going to have this as long as he lived, damn it, because he wasn't letting go.
He almost laughed at the impossibility of it.
It was like the world had suddenly taken color. It was like standing in a church in the dark, motes of dust about him- and then the sun had risen, sunlight streaming through the stained glass window, gorgeous greens and dazzling oranges, beautiful blues and lively yellows, a chorus of joyous voices rising into the air, everything bright and gorgeous and so perfect he felt like he might cry, and he really did laugh, now.
It was only scant hours later that Ianto felt himself dying, tears on his face that could be his own and could be Jack's, and he only wished that he could have gotten to hear the thousand little stories he'd always wanted to know, the ones that barely mattered. Not the Doctor, not Jack delivering a dozen children to some drug-hungry aliens, not the burials and funerals and dead aliens. Just his wedding. Weddings. Whatever. The birth of his daughter. Conning the queen of France, sleeping with her 'incontinent' husband. Flexible acrobatic twins. The stories that made Jack smile.
His life and death wrapped up in Jack Harkness. He had no regrets.
It had been good.