This is my version of what happened after series 2. I introduce my OC, Willow, and her race is a creation of my good friend Verity.

Hope you enjoy this first part.

xoxoxo

Jack, Gwen and Ianto were in the hub, trying to come to terms with losing Tosh and Owen the previous week. The Rift had been quiet in that time, with only the occasional rogue Weevil; as though it too was mourning them. Ianto was passing round the usual coffee as Jack's phone rang. They tended to stay in Jack's office now that there was only the three of them. The hub seemed too quiet and empty without Tosh's bleeping equipment, and Owen's sarcastic comments. Only now did the team fully appreciate them. Jack sighed, knowing that it was bound to be one of the international Torchwood's, offering them one of their employees as a replacement for Tosh or Owen.
"Torchwood Cardiff. Jack Harkness speaking."
A woman's voice rang through from the other end.
"Good afternoon, Mr Harkness," Jack raised an eyebrow. Captain, he thought. "This is Ida Jones from Torchwood Paris. I heard of your...predicament from Torchwood Glasgow, and I'm calling to offer you my condolenses, and our services."
"And, which 'predicament' would that be, Ms Jones?"
"Well, we know you lost two of your members a short time ago, and..."
Jack was getting agitated, and ran a hand through his hair.
"Yeah, last week."
"And I was just calling to see how you were coping."
"We're coping fine, thank you very much," Jack swallowed. "I appreciate your offer, but we really aren't looking for anyone else at the moment."
"Oh..." Ida paused. "The thing is, she's already on her way..."
"What?" Jack was furious. "Who authorised this?"
"I-It was the head of Torchwood Glasgow...Arnie Head."
Jack sighed.
"Alright, you'd better get me up to speed."
"Her name's Willow Sharapov, she transferred here from Torchwood Tokyo. She's a weapons expert."
"Alright. Anything else?"
"She...she's, er, not exactly...human..." Ida paused and, when Jack didn't speak, continued. "She's Sitian...she can change her appearance at will..."
Jack sighed, again running a hand through his hair.
"She's civil, though? She won't compromise how the team works?"
"No, not at all. She's completely harmless."
"Alright...when should she be arriving?"
"Couple of hours, give or take."
"OK. Thanks."
Jack put the phone down without waiting for a reply and sighed, turning to look at Gwen and Ianto.
"Look, I know we're still getting over Tosh and Owen, but we have to carry on. For them. We've got a new recruit coming over from Torchwood Paris. Willow Sharapov. Weapon's expert."
Gwen and Ianto nodded.
"OK, we'd better get this place tidied up," Jack looked around the hub. It was a tip. As Gwen and Ianto headed for the door, Jack spoke again. "Oh, and one more thing." They turned back. "Ms Sharapov...she's not human." Jack grinned at the looks on their faces.

Two hours later, Ianto was waiting in the Tourist Information Office for Willow, leaving Jack and Gwen alone in the hub.
"So...how are things with Rhys?"
"Oh, you know...even though he knows about this place, he still moans that I'm never home."
Jack grinned.
"Well, if you were my wife, I'd..." he paused, immediately regretting what he had just said. "I'd be worried if you spent all your time cooped up in this hub with your attractive 51st Century boss."
"Now Jack, don't be getting cocky," Gwen smiled.
Jack looked at her, brushing a lock of hair from her eyes. Gwen swallowed as he tilted her face so she was looking at him. He started stroking her hair softly, smiling at her. She smiled back and, just as Jack went to stroke her cheek, the cog doors rolled back revealing Ianto and their newcomer, Willow Sharapov.
Compared to the rest of the team, Willow was tiny. She was barely the height of Ianto's shoulder. Her long brown and red hair fell to her waist. She had bright green eyes which rivalled Jack's for their intensity. As she entered with Ianto, Jack hurriedly stepped back from Gwen and smiled at Willow, stepping forwards and holding out a hand.
"Captain Jack Harkness."
Willow shook his hand, looking around the hub in awe.
"W-Willow Sharapov..."
"You already know Mr Ianto Jones," Jack gestured towards Gwen. "Gwen Cooper, second-in-command."
Gwen stepped forwards and shook Willow's hand.
"It's actually Gwen Williams," she held up her wedding band. "Jack just conveniently decides to pretend not to remember."
She and Willow giggled.
"Ianto will give you the grand tour," Jack smiled.

Half an hour later, the team were gathered in the boardroom, and Jack had brought Willow up to speed with the Rift and the Weevils. She had been amazed by the creatures, commenting that there weren't any in Paris.
Jack's mobile went just as he finished talking.
"Yeah, hello?"
"Jack? It's Martha."
Jack jumped up.
"Oh yeah...I forgot you were coming," he laughed. "I'll come let you in."
Jack gestured to the others to follow him as he walked out into the hub, bringing down the lift as he does so. As the lift ground to a halt, Martha Jones stepped off, hugging Jack as soon as her feet found the ground.
"Welcome back."
"It is so good to see you, Jack. I was sorry to hear about Tosh and Owen..."
She hugged Gwen and Ianto in turn before turning to Willow.
"Martha Jones. Medic."
"Willow Sharapov. Weapons."
They shook hands, and Jack beamed at his new team.

Jack, Gwen and Ianto looked at one another as Tosh's Rift activity detector started bleeping.
"Don't look at me," Gwen started. "She never told me how to work it. I don't think she trusted me with it," she added to Willow.
Willow made her way to Tosh's computer, examining the screen.
"OK, so basically, we have Rift activity here," she pointed at a beach. "It wasn't a very big spike, so I'm guessing it was probably just another Weevil slipping through, Captain."
Jack gawped at her.
"So what, you're a computer genius as well now?"
She grinned.
"I just pick it up as I go along, Captain."
Jack smiled, jumping into action.
"OK, Gwen, Martha with me. We need to get whatever this thing is before it gets spotted by any dog-walkers," they nodded. "Willow, I need you to stay here, let us know if there's any more Rift activity," he passed her a comms device. "Ianto, I need you to stay with Willow; I don't want to leave her on her own on her first day." Ianto nodded. "Keep your comms open at all times." Jack left with Gwen and Martha, passing the latter a comms device on the way out.
"This is where the fun begins," Ianto smiled. "I meant to ask...how do you take your coffee?"

When Jack pulled the SUV to a halt at the location Willow had fed through to him, the beach was deserted. He jumped out of the SUV, Gwen and Martha behind him, and looked around.
"You sure this is the right place, Willow?"
"I'm certain, Captain."
"OK, we'll do a quick sweep of the area. Seems quiet th..."
Jack paused. He had heard a scream. Gwen's scream. Heart racing, he drew his Webley, looking around for a sight of Gwen.
"Martha! Gwen!"
"Jack?" Ianto's voice rang through the comms, urgent, shaking.
Martha was lying on the ground. She was out cold. Hearing the screech of a car, Jack spun on his heels just in time to see a red van speeding off. Jack caught a sight of Gwen, gagged and bound in the back, before the doors closed.
"Gwen!"
Jack raced forwards, aiming his shots at the vehicle's tyres, but he was too far out of range.
"Damn! Willow, Ianto, I need you to track and trace a red van. Registration Charlie Delta 08 Lima Golf Romeo. Keep an eye on Gwen's comms signal as well. They've got her."
Jack raced back to Martha as she regained consciousness, helping her to her feet.
"What happened?"
"I...I dunno...I was taking a look around, next thing I know, someone's hitting me over the head with something...Where's Gwen?"
Jack swallowed.
"Someone's kidnapped her. I've got Ianto and Willow working on it now. And believe me, when I get hold of them, they're gonna wish they'd never been born.