"You'll be careful won't you?" She demanded, searching his face as she held onto his hands.

They stood near the door of her room, neither of them wanting to leave but knowing they had no choice.

He was wearing his backpack, which contained among other things a bomb they had prepared to take out the control center. The shapeshifters would shut down automatically if the computers in there stopped working, as a safety measure because even their creators had know they were dangerous uncontrolled.

Other than that she was perfectly fine with his backpack, it was the bulletproof vest which set her teeth on edge and caused her stomach to squirm and knot painfully.

"I'll be fine," he assured her, kissing her forehead. "I'm more worried about you to be honest, going in to warn those business people all on your own. Couldn't Trip or Coulson-" he fretted.

"They have their own people to warn about the shapeshifters," she informed him. "And besides, we know the one in that company is out of the country. It's nowhere near where I'll be. All I need to do is tell them not to let it make any deals."

"Yeah, you're right, you'll be fine," he agreed nodding perhaps a bit too enthusiastically. "I'll see you in a few hours."

"Only a few hours," she nodded back trying to be optimistic but her eyes drifted back to the vest and her heart clenched fearfully.

She wrapped her arms around him and pressed the side of her face against his. "You come back to me," she whispered, feeling him pull her close.

"And you come back to me," he murmured. "Don't get stuck in an elevator or something."

"As if you couldn't fix an elevator," she teased, soaking in the feel of his body against hers despite the stupid vest.

No, not stupid. She liked the vest just not the reason he was wearing it.

Sometimes she wished she was the bloody engineer always getting called off into danger. Wasn't there ever going to be a high risk biochemistry mission? Like pipes leaking acid or bad guys made of goo. Damn his knack for making explosive devices.

Not that she hadn't helped, creating the chemical components among other things, but it was him who was the master of rigging them to go boom just when you needed them too. Like on a hazardous mission into a secret base of monsters who made monsters.

But they were agents of Shield and that meant that, sometimes, they needed to let each other go and have faith nothing horrible was going to happen.

It didn't mean she had to like it though.

"Take this," she instructed, removing her necklace and placing it around his neck. The pendant formed a heart at her touch because she was thinking of him.

"But this is yours," he objected.

"And I expect to get it back," she informed him, kissing him before tucking it under his shirt.

"I'll keep it safe," he vowed.

"You'd better," she answered before embracing him again. "Be careful sweetheart." She pleaded before kissing his cheek and forcing herself to move away.

"You too Jemma," he said, smiling warmly at her and melting her heart.

"Ready to depart agent Fitz?" B21 inquired, popping into her room and placing Leo's gameboy onto her bedside table. It had moved on from Pokemon to Zelda after defeating the elite four. (A misleading name considering there were five.)

"I'm ready," he told it and Jemma walked them out to meet Skye and May.

She hugged Skye and then Leo one more time and smiled at May before urging them all to be careful.

"And you take care of them," she instructed B21.

"I will," it complied. "I will keep your dear ones safe."

She was surprised at the use of such an affectionate term but she supposed an adjective was an adjective to a machine.

"Good," she praised, touching its arm. "I'm glad we understand each other."

It smiled at her and she watched them leave, part of her leaving with them.

She closed her eyes, pushing down her apprehension before returning to her room and preparing for her own mission.

/-/-/

Leo, Skye and May made it smoothly into the building. Mr. Mendoza was tied up in the back of their truck, knocked out by an ICER and B21 now took his form.

It led them in, introducing May and Skye as its body guards and him as a consultant.

'I could be a body guard too,' he'd thought grumpily at his assigned role however he hadn't complained out loud.

Once inside B21 had began its 'inspection' leading him first to the control room where he placed the bomb and rigged the timer to go off in thirty minutes. Hopefully that would give Skye enough time to erase all the data. She didn't need to hack in because B21 had access so they weren't expecting it to take long.

It was all going far too well and he was preparing himself for catastrophe on their end when Jemma's panicked voice reached them across the coms.

"Umm... How long until the shapeshifters are shut down exactly?" She wondered, the fear in her voice making his skin crawl.

"Ten minutes," he told her looking up at Skye who gave him a thumbs up to communicate she was nearly finished.

"Ohh... OK," she squeaked. "Ten minutes everyone, I'm sure the glass will hold."

"Jemma?!" He exclaimed. What the hell was going on? She was supposed to be fine, she was on the safe mission.

"What's happening?" May demanded.

"Well, the shapeshifter came back early...," she told them, unsuccessfully feigning calm. "The other company backed out of the deal and well... It knows we're onto it."

"What?" Skye exclaimed and Leo felt sick with terror. "Simmons! Are you OK?"

"Everyone is fine, everything is absolutely under control...," she assured them nervously but he didn't believe her,"...for the moment. We put the building into lockdown and it can't get through the stairwell but... I mean we're twenty stories up you can't really blame whoever designed the security not to expect... and the window is made from four inch thick bulletproof glass but... We'll be fine. Just wanted to know how long we'd be up here," she laughed anxiously. "Mr. Duncan wants to make popcorn don't you sir?"

"I'm g-good for now," he stuttered and there was a loud bang.

"Jemma!" Leo cried.

"We're fine," she chirped. "It's just trying to get in. No reason to panic everyone, it may have been clever enough to use a window cleaning perch to get up here but fortunately it doesn't seem to know how to get in. That window should-"

There was another loud bang followed by a crack that seemed to tear down Leo's spine before several people began shouting.

"It's breaking it!" "Oh my God!" "It's gonna kill us!"

"No!" He screamed. This had to be a nightmare, some horrible nightmare but it wasn't.

"Calm down," she soothed. "It's only a tiny crack, we'll be fine-"

Bang!

"We'll be fine," she kept saying. "It's going to turn off soon. We have good people working on it."

This seemed to quiet the others and the shouting stopped.

"We need to go," May told him, pulling his arm. He resisted for a moment before he remembered that Jemma was miles away, not there.

They ran out of the building and he listened to brave, wonderful Jemma keep the business people from panicking while he flinched at each bang. His heart ripped painfully each time he heard a crack.

Two minutes left, it wasn't going to get in, it couldn't.

'Please, not her,' he thought desperately. 'She has to be OK.'

They were at the elevator when the timer reached zero but nothing happened.

There was no low rumble of an explosion and after a few seconds they heard another bang.

"Is it going to go off soon?" She wondered, her voice starting to tremble.

The world spun around him. Why hadn't it gone off?

He had to make it explode, those people in the building deserved to live and she couldn't die. That was unacceptable.

Without thinking he dashed back towards the room, almost running into the wall of armed guards who rushed out to block his path.

May shouted his name and shot at them as he slipped by and B21 followed behind him, protecting him from their shots with its body.

"Skye? May?" He panted, not breaking pace.

"We're fine just go!" May ordered.

Not that she needed to tell him.

Someone, a shapeshifter, leapt at him and B21 intercepted it while he ran on.

He finally reached the control room only to find the bomb had been tampered with, probably by the shapeshifter from the hall.

He cursed loudly and felt tears escape his eyes as another bang preceded a loud crack across the coms.

"Jemma?" He asked, his chest tight.

"It's holding for now," she informed him and he let out a shaky breath of relief. "What is going on?"

"The bomb was disarmed," he explained.

"But you can fix it right?" She inquired quietly.

Yes. He could because Jemma could not die.

"Yes," he assured her, setting to work.

/-/-/

"I can fix it," he told her suddenly after a minute but there was a solemnity in his voice that sent cold tendrils of dread uncurling through her.

"Why do you sound like that then," she asked anxiously.

"Because I can't fix the timer," he replied flatly.

"Then you're not doing it," she told him firmly, despite the cracks which were beginning to spiderweb across the glass. He meant he could fix the bomb but he would be caught in the explosion. That was unacceptable.

"Jemma-" he began.

"No!" She cut him off, not wanting to hear his argument, not wanting to hear there was no other way because there had to be. He had to come out of this.

"Jemma you were right, yesterday at the Shield facility. You were right that we can't put our own safety, our own lives even, over the people we need to protect." He reminded her bravely. "I'm willing to give mine for those people in the room with you, for you."

"I don't want you to," she protested her voice high and scared. "We'll fight it, we have a fire extinguisher and... and..." But she knew she was being irrational, ridiculous. They could never win and it wasn't only her life at risk.

"It's OK," he said softly and the clicking of wires across the coms told her he'd started rearming it.

"Don't!" She screamed. The others were staring at her, frightened. "We'll be OK," she assured them, feigning a smile and hoping she sounded convincing.

"Yeah, yeah you will be," he agreed trying to sound cheerful. "Jemma I'm sorry but I'm gonna need to use your necklace, they took part of the-"

"I don't care about the necklace!" She shouted, her eyes filling with tears as she realized this was really going to happen. It knocked the breath out of her like a blow to the stomach. "I meant you! I wanted you to come back."

"I know," he soothed. "But I can't."

"Yes you can!" She argued fiercely. "Just..." But she could see no other way. The shapeshifter bashed against the glass again and a long crack snapped across the window. If they didn't turn it off soon it would get in and it would kill them all.

One of the business people screamed as it threw itself into the window again with an awful crack.

"Just... We can... You can't..." She squeaked miserably.

She couldn't let this happen. She couldn't let Leo die again but he was going to.

"I love you," he told her and she felt his words like a warm embrace despite the horrible terror they brought with them. She knew what was coming next.

"Don't," she whispered.

"Jemma please," he begged and she knew he needed her to say it. Even if he knew she loved him he needed to hear it one more time and if this was really goodbye she needed to say it or she would regret it forever.

"I love you too," she whispered trying wrap her words around him as his had done to her, trying to communicate to him with more than just words everything he meant to her. "I love you and you're amazing and you make me happy and the world is better with you in it and... Please don't do this." She pleaded.

"I have to," he said gently. "There's no one else who can-"

"I can do it," B21 interrupted across the coms.

"You're to far-" he began.

"I will make it, I am on my way." It informed him and Jemma felt as if a large stone had been lifted from her chest. "Do not set it off yet."

Another crack sped across the glass and several people began screaming.

"Jemma?" He called alarmed.

"We're fine," she said quickly. "It's not in yet. Wait for B21."

"Wait for what?" A man exclaimed over the loud banging against the glass. "Can he turn it off? Do it now! Before they get in!"

"No!" she yelled. "He'll die if he does it now. He is willing to die for us, all of us but he doesn't have to. He doesn't have to!" She repeated more forcefully into the coms. "We need to wait for B21."

"It's going to get in!" A woman yelped.

"Jemma if it gets in there-" Leo tried to say.

"Shut up!" She commanded. "All of you need to shut up and let B21 get there."

That had probably been way too harsh for a terrified crowd of civilians but she wasn't going to let them goad Leo into getting himself killed.

"I'm there," it told her. "Agent Fitz please leave. You should run because I need to hurry."

"Just put that wire back into the slot," he instructed sadly.

"There is no time for you to display your affection," it scolded and she knew he had hugged it.

"Thank you," he said gratefully

"Thank you B21," she told it. "I'll miss you, if that means anything to you I'll miss you."

She didn't know why it was doing this, if it was following her orders or if it actually cared about her and Leo, but she did know that it didn't want to die. It was afraid but it was doing it anyway and whatever the reason she needed it to know that that mattered to her.

"I'm proud of you," she told it as Leo bolted away to safety. "You are being so brave and it feels like you're saving me too, do you understand that?"

"It is love," it stated and she wasn't sure if it meant that as an expiation for her feelings or its actions or both.

"Yes," she praised it, a tear sliding down her cheek. "That's love."

There was an explosion which she heard from a distance on Leo's end of the coms and the shapeshifter outside shut down, crashing to the floor.

The room cheered.

"Leo?" She gasped, he was fine, B21 would have made certain he was far enough away but she still needed to hear his voice.

"I'm here," he said quietly. "Are you OK?"

"We're all fine," she announced, gazing around at the giddy, smiling faces and laughing in relief. "Everyone is fine."

Everyone except B21 she thought with painful flicker of sorrow. Whatever the shapehifter had been it had saved Leo, herself all these innocent people. And she hadn't been lying when she'd said she was going to miss it.

/-/-/

He saw her exiting the building with the others and the moment their eyes met they broke into a run, slowing slightly before they met so not to crash.

They held onto each other crying out of both relief and sorrow and neither of them spoke but they understood what the other was thinking without words.

How glad he was to have her in his arms again, to be together.

"How about next time we switch and I set off the bombs," she suggested.

"You can make sticky goo to put inside them," he kidded. "Or stinky smoke."

They laughed together for a moment before she pulled away, her eyes bright. "B21..." she wondered.

He shook his head. "It's gone."

She nodded, her lip trembling and he felt his own eyes grow hot as he pulled her back towards him.

"I know it was only a m-machine... but..." She sniffed.

"It saved us," he finished, tears spilling out. "We can't know what was happening in its head Jemma but... If it did care it would have been glad for what you said to it."

She sniffed and rubbed her back soothingly.

The rest of their team showed up and Skye and Triplett joined their hug while May and Coulson smiled at them.

Coulson had called for back up and the shapeshifters creators had surrendered. It was over and by some miracle everyone was safe. Jemma, himself, all those people were alive because of one of their creations. B21, whatever its motives had been a great force of good born from their evil and he was grateful for it. Like plutonium powering a city and bringing light out of darkness.

/-/-/

They placed a tombstone under a willow tree even though they had nothing to bury. B21 was inscribed in the rock and Jemma wondered if passers by would think it a strange joke.

They thanked it and each of them placed a flower down in front of the stone.

She cried, in spite of her best efforts not to and Leo held her close and cried with her. She would never forget that B21 had given its life for his and probably hers too.

She was so glad to have him still, her Leo. Brave and kind and unquestionably irreplaceable.

/-/-/

Thank you for all your reviews, likes, follows and reads! you are all wonderful lights :).

A special thanks again to notapepper for all their help with figuring out b21.

the fringe reference is when Jemma is thinking she can't let leo die again but he is going to. in what lies below, Walter says the same thing when his son Peter is infected, prompting a ?_? from Astrid.

You have reached the end. hooray! congratulations and thanks for reading! I hope you enjoyed it.

B21 motivations are purposely left ambiguous. was it only following orders or did it want to save fitz? what do you believe?

The plutonium thing is from a quote by Fitz in the show. I forgot to mention that last chapter.

Mr. Duncan is named after the Mr. Duncan in Orphan Black.