The first time he heard it, Jack almost wasn't sure what it was. Oh, it was a laugh, that much was clear, but no one else on the team had that rich timbre that Ianto had, so Jack was a bit thrown. It wasn't one of Ianto's ironic laughs, frequently accompanied by an eye roll. Nor was it one of his nervous laughs, like when Jack whispered something naughty anywhere but in bed.

Jack just listened for a moment, then turned and looked. Sure enough, there was Ianto, sat on the floor in the Hub, playing with their latest visitor, a small, furry creature about the size of a baby bunny.

There wasn't much difference between it and an earth-rabbit, except that it behaved more like a bouncy kitten. It was just Ianto and Jack, waiting for one of their alien contacts to stop by the tourist office and pick up the little ocsid, a common domestic pet on planet Bradbury in the Crab Nebula. Ianto had just retrieved the alien from its holding cell and decided to tire it out so that maybe it would sleep on the way back to the alien safehouse, where it would hopefully settle in as a companion for some residents who weren't humanoid enough to go out frequently.

But that laugh had Jack captivated. Ianto laughed again as he dangled the old shoestring in front of the ocsid and watched it bouncing up to try to catch it between its opposable ears. Jack had heard many sounds from Ianto, beyond the usual Welsh vowels and dry tones, and Jack realized just how few of them had been joyful like that laugh. Mostly what he'd heard from Ianto in the time he'd known him were sounds of pain or anger or despair – things strong enough to cause composed Ianto Jones to cry out. Even when Ianto was crying out in pleasure, that wasn't quite the same as plain, uncomplicated merriment.

For as happy as Ianto sounded, it saddened Jack. Maybe they shouldn't have been so quick to rehome the ocsid. Although he'd thought it would be unfair at the time to add another 'inmate' to the list of creatures Ianto cared for, pteranodons weren't exactly pets, and certainly not Weevils. And Jack knew he'd love to hear that carefree laugh again, and as often as possible.

"You seemed to be making a new friend," Jack said, his hand on Ianto's back as they watched Ger the Siloportem head off down the bayside boardwalk with the little pet carrier. "I almost wish we'd kept it now."

Ianto glanced up at Jack with a small smile and shook his head. "It was cute, but they need it more than we do, Jack. It's a pretty hard life for some of the fellows over there."

"That's my Ianto, selfless to a fault," Jack said, trying to sound teasing.

Ianto shrugged. "Well, maybe. But it appears our day is done and we're the only ones left here. And I'm feeling a bit… selfish," he said with a grin.

Jack grinned and closed and locked the tourist office door firmly. He turned to Ianto, settling his hands at Ianto's waist. "I like selfish Ianto," Jack murmured, pulling Ianto into a kiss.

It was several months before Jack heard that laugh again. He and Ianto had sneaked off on the premise of checking in with one of the safehouses in Llandaff, which naturally resulted in a picnic in Bute Park while they were in the neighborhood and it was temperate and not raining.

They decided to stop at a café in the park to pick up lunch, sandwiches, a couple soups, and a few of Ianto's favourite onion bhaji. Since it was such a warm day, they both opted for cold sodas as well, instead of coffee or tea. Finding a quiet spot beside the river, Jack spread out the blanket they'd brought and stretched out.

He could have skipped eating altogether and just lie there beside Ianto, listening to the running river and all the various singing birds. It was probably the most peaceful moment Jack had in months… if not years. Jack just closed his eyes for a few moments and listened. And that's when he heard it again. Ianto's rich, full laugh.

Jack opened his eyes to find Ianto watching a couple of pigeons milling about near their blanket. One pigeon was puffed up and strutting circles around another, while the other constantly diverted the puffed-pigeon out of its way. Jack propped himself up and chuckled at the two birds.

"He's got no idea his advances are going to waste, has he?" Jack said.

"He reminds me of Captain Jack Harkness," Ianto snickered.

Jack's jaw dropped and he stared at Ianto. "What do you mean? I don't puff up!"

Ianto looked over at Jack and snorted in disbelief. "Yes you do, all the time. And you stalk around your prey just like that as well. You flirt just as mercilessly as that rock dove."

Jack huffed indignantly. "Well. I'd at least like to think my efforts aren't as wasted," he pouted.

"Of course not," Ianto said soothingly. "Well, maybe not anymore. I think I was that other bird at first, though."

"Yeah, you were. Pretending not to be interested, rolling your eyes, warning me off harassment." Jack gave a laugh. "As if."

Ianto just smiled and passed Jack a bottle of soda.

"Thanks," Jack said, as Ianto turned back to the carrier bag.

"I recommend not op-"

"AAAHHH!"

Ianto sighed. "Not opening it straight away." He turned to see Jack sprayed with red splashes of cherry Vimto. He couldn't help it, throwing his head back and cackling. Jack pouted pitifully, covered in sticky soda, and Ianto tried to quash his laughter, but it only made it worse.

Jack couldn't manage being annoyed, not when Ianto had that uninhibited laugh. After a moment, he found himself laughing along with Ianto and shaking his head.

"Here," Ianto said, still trying to control his laughter and fishing in his pocket for a packet of wet serviettes.

"Thanks, Ianto," Jack said. It was well worth being a bit sticky to hear that incredible laugh again. If the rest of the day went their way, Jack was looking forward to getting sticky in other, more enjoyable ways.

The next time Jack heard Ianto laugh freely it had been such an incongruous sound, especially in the months since the last time he'd heard it. There hadn't been much time for laughter since their team had been reduced by two.

And then there was the fact that the world was probably ending, yet again. At least this time it had plenty of other planets for company. The three of them were working on the problem as much as they could from their end.

Ianto stood at his workstation, reviewing whatever clues were available through various news media. It was getting a bit repetitive and Ianto had started looking for data outside of standard channels of journalism, trying the often overlooked chat-show formats instead.

Jack was worn out and hoping for a long sleep that night, even before the earthquake hit. When he'd stepped out on the pavement to assess the damage locally and found the sky filled with other planets, his blood ran cold. Whatever was happening was not likely something the three of them could manage, even if they could call in favours from the local constabulary.

When Jack heard Ianto suddenly laugh out loud, that unstifled, immodest guffaw that was almost uncharacteristic, Jack had barked that it was inappropriate. And he hated himself for it immediately. Just because his nerves were raw and ragged, he had no place taking such a tone or suppressing whatever form Ianto's coping took. He knew perfectly well that Ianto wasn't skiving off or not taking the situation seriously. It was just… Jack was scared, and he never dealt well with real fear, and it had just come out wrong and he wished more than anything he had just a minute to spare to apologize. If things went wrong and he never got the chance….

Ianto hardly even seemed to notice Jack's sharpness, though. He just shrugged it off and came to help Jack analyse the situation at hand. But that was Ianto, never taking personal offense, always there to help.

That had been the last time Jack had ever heard that particular laugh. Months later, Jack stood on the boardwalk, looking at what had once been the entrance of a rarely-open tourist office. He remembered that laugh more than anything. Of all the coffees they'd shared, of all the long talks, of all the hot sex, it was three times he'd heard Ianto laugh openly, loud, unselfconsciously, joyfully - that was the thing he missed now so much. Over a playful little alien pet, over a flirtatious pigeon and a soda-sprayed Jack, and over a stupid quip about the sky being full of planets.

It was the rarest sound in the universe, and Jack would give everything to hear it just one more time.