Author's note: When I published the last story in the Step universe (Step Fourth), I really really thought that was the end for a while. I have a lot going on at the moment, season 4 is coming up, there are other stories I want to write for other shows… But then Sasha and co tapped me on the shoulder repeatedly with a story idea, and eventually it got too loud for me to ignore.

So I'm not sure how many chapters this will end up being, or how often I'll be able to update, but here you go, the first chapter of Step Forward. Rated T for now, but I may succumb to my love of smut later on and upgrade to an M.

This story is a bit of a different direction, so more than ever I would really appreciate a review to let me know if you're on board!

Chapter 1 – Bring it on

Sasha Chandler ended the call and set her cellphone on the kitchen table, her forehead still creased into a frown. She stared down at the notes she had begun scribbling five minutes into the conversation, once it became clear that Second Lieutenant Kathleen Nolan of the US Marine Corps - aka Tex Nolan's daughter Kat - wasn't just calling for a friendly chat.

Sighing, Sasha picked up her phone again, scrolling through her contacts and vacillating between two different options: her boss at the National Intelligence Service, and her close friend – and more importantly, eminent scientist - Rachel Slattery. Then she had a brainwave and chose a different number entirely.

"Sash!" At her home a couple of miles away, Nina Callaghan answered the phone on its first ring, hoisting her two year old son over the table and into her husband's arms as she did so. "How are you?"

"Can you talk?" Sasha sounded worried, and Nina sat down at the table, making a face in response to her husband Tex's puzzled look.

"Sure. What's going on?"

"You still talk to a lot of other journalists, right?"

"Well, the ones that are left. But people, sources... yeah. Why?" Instinctively, Nina pulled a pen and a piece of kitchen towel towards her.

"Have you heard anything about an Immune resurgence on the West Coast?"

When Admiral Tom Chandler got home, his two elder children in tow, he found his wife feeding chocolate pudding to their infant twins, Amelia and Jed, while simultaneously scribbling on a pad and talking on the phone.

"They're claiming the cure is no longer effective-" Sasha stopped abruptly and he could hear the raised voice of the person she was speaking to, though he couldn't make out the words. "Yes, I know that, Rachel," Sasha continued, "I'm saying it's what they're claiming, not-" She looked up and saw Tom watching her, and she smiled. "Tom and the kids are home," She told Rachel, "I'll call you right back."

"What's happening?" Tom asked, as Sasha ended the call, and stood to kiss him in greeting.

"Something." She replied. "I'll tell you all about it once these two are in bed. In the meantime, can you handle bath time while I handle dinner?"

A couple of hours later, with the twins bathed and put to bed - evidenced by damp patches still drying on Tom's shirt - and Ashley and Sam closeted in their rooms, Sasha sat down next to her husband on the couch and took a deep breath.

"Do you think you could cope here if I went away for a little while? Probably a fortnight at most?"

"Sure..." Tom replied slowly. "But why would that be happening?"

"There's been a resurgence of Immune activity on the West Coast. It's coming out of a small town in Southern California. I want to go and check it out, and the NIS are on board."

"Why you?" He asked, and something in his tone needled her just a little.

"Because it was flagged to me. And because I can assemble the right team. And why not me?" She couldn't resist adding. "The twins are a year old now, and maybe I could do with something outside of this house!" The words were out of her mouth before she'd had time to think, and she watched Tom react.

"You feel like that?" He asked quietly.

She swallowed before nodding. "Yes, I do. I love being a mom, and I love our family and our home, I do." She paused as she tried to make sense of it out loud in a way that Tom would understand. "But I love being out there too, and I think it's time I tried to find that balance. Sifting intelligence from our couch is never going to be enough for me." She held her breath as she waited for his response.

"Sash..." His eyes softened and he reached out to pull her into his arms, "I love that side of you. I'm sorry, I guess I thought you were happy here."

"I am happy! I just need... more." She couldn't help laughing a little at how that sounded, and Tom let out a chuckle.

"That's my wife, always wanting more." He kissed her. "Of course I'll handle things here. You go do your thing. You'll have a team with you, right?"

"Absolutely." Sasha replied, sinking into Tom's embrace as the kiss deepened. She decided to wait a while before expanding on exactly who that team consisted of.

The next morning, Sasha drove into the city to meet her team in the coffee shop in central St Louis that they'd been frequenting since first settling in the city after the apocalypse. When she arrived, Nina Callaghan was already there, alongside her step daughter Kat, who had swapped her service uniform for jeans and a leather jacket.

"Undercover, huh?" Sasha greeted her.

"That was the condition of me being allowed to do this. No overt military presence, right?"

"Right." Sasha nodded, noting out of the corner of her eye how proud Nina looked. "Tex okay about you both doing this?"

"Are you kidding?" Nina replied, "He's just pissed off that he wasn't invited."

Kat laughed. "That's not completely true. But he's made me promise to protect Nina and-" She broke off abruptly and winced, and it was only Rachel's arrival that prevented Sasha exploring that further.

"Hi!" Rachel Slattery (nee Scott) seemed oblivious to the stares that she automatically got whenever she went out in public, but as she hugged them all in greeting, at least a dozen pairs of eyes were on her. Sasha noted with satisfaction that Kat was subtly scanning them, just as she herself was, to ensure there was no threat. It might have been three years since Danny Green and Carlton Burk had foiled the attempt on Rachel's life, but no one had forgotten it.

Once they were settled with coffee, Sasha outlined her plan.

"As Kat and Nina both have contacts in the town, we go in low key and start gathering intel, see where it leads. This is purely an intelligence mission, not any kind of action or takedown. We need to establish facts on the ground and pass those back to NIS and Military HQ, who will decide on a suitable strategy to neutralise the threat. Rachel, you'll be our scientific adviser. Everything we get on their claims about the virus and the cure, we'll pass back to you for vetting. It may be that we're asked to start a subtle whispering campaign to counter their claims with facts, so you'll be vital in helping us to do that." Sasha paused as she saw Rachel looked puzzled.

"You're talking as though I won't be there with you?" The scientist asked.

"Well, yes." Sasha quickly glanced at Kat and Nina. "You'll be here, we'll send the information back via a secure-"

But Rachel was already shaking her head. "They're claiming new infections. I can't assess that from afar. I need to be there."

"Rach," Nina laid a hand on her arm, "You're one of the most recognisable people in the world. This is a covert operation."

"So I'll wear a hat! If you honestly think you can do this without me-"

"We can't." Sasha spoke as bluntly as she could. "But you can't be in the field."

"She could stay in the house." Kat said, "We drive in at night anyway, unlikely anyone would see. And it means Rachel can be close to the action without being identified." Kat's voice had a quiet authority that belied her age, and nods around the table signalled consensus.

"Have you told Mike yet?" Sasha asked.

Rachel shook her head, "I wanted to hear the plan first. He's going to want me flanked by six large men with guns, so I need to talk him round." She sighed.

"How about two large women with guns?" Sasha asked, unable to resist a slight smirk.

"Three." Nina corrected, and then raised an eyebrow at the looks of surprise. "Oh please, you don't think I have that in my skill set?"

It broke the tension that had accumulated, and even Rachel managed a smile as the others laughed.

"So when do we leave?" Kat asked.

"I need to write up the briefing and get it signed off, and there are a few intelligence sources I want to speak to here in St Louis, but in theory? No later than the weekend." Sasha replied.

It was Nina who said it, but all four were thinking it: "Bring it on."