This is a AU I guess. More or less an alternate ending to the movie. You should be able to figure out at what part it is. And to make things easier in here 4 is a girl and 3 is a boy.

7 figured that if she had a heart it would be the only thing she could hear right now. The dull pounding, adrenaline causing the beats to speed up way beyond what was considered healthy, reflecting her own fear and tension. Echoing about in her mind, making it hard to concentrate. Making it almost impossible to locate where the machine was, waiting in anticipation to strike.

Even though she didn't have a heart, she could feel all of its effects in that moment.

She tightened her grip on 3's hand and leaned closer to the fence post they were hiding behind as a flare of dust erupted into the air, suggesting the machine had thrown another object their way. As soon as they had made it across the bridge, 9 had left them. He had run off, foolishly following 6's last words. Yes, it had hurt to see 6 taken from them like that, but to 7 that only made the desire to destroy the machine grow stronger. This metal beast had ripped her family away from her, all those she had known and loved, and she wasn't going to let that go unpunished.

They had tried an offensive, using an old turret system to shoot at their enemy. This had been 1's idea, and for once in her life 7 had gone along with what he ordered her. This was a do-or-die situation. One shot had reached its target out of several, but it wasn't enough. Before they could take another, the machine had destroyed their weapon, causing the small group of stitchpunks to disperse. 7 had taken charge of the twins, rushing them over to the fence post where she now hid. She had lost track of 1. Most likely he was cowering all by himself, caring more about his own safety than hers or the twin's. Selfish old coward.

Another blast into the earth, this time only a short distance behind their hiding spot. 7 looked up at the red sky and prayed that 9 would come back soon with some sort of solution to all of this. Sure, he had been the one who caused these problems in the first place, but that gave him the determination to right his wrongs. She had seen how desperate he was to rescue her, which he did successfully, and to save 5 and 6, which didn't turn out as well. If anyone could get them out of here safely, it was him.

There was a mechanical groan that sounded like it came from right next to them. She absently groped around for her spear, then remembered that she had dropped it back by the turret. Not that it would have helped. She hadn't been able to defeat the beast they had dubbed 'The Seamstress' with it, and that had to be the most dangerous machine they had faced. Until now. This machine, the B.R.A.I.N., was larger, more solid, and possessed the only item that was known to drain all of the life out of a stitchpunk: the talisman which 6 had been obsessed with. The Source.

Normally 7 would be considering all of her options for an attack, a way to bring down her adversary, but she had run out of alternatives. There were no other weapons nearby, and it wasn't worth going out into the open to find one and risk being spotted. All of her instincts told her to put her own safety aside and just do it. Tempt death for the slim chance that she would be able to slay the beast. In a normal circumstance this was exactly what she would do. But this time she wasn't just hiding for herself. Without her being around, the twins would be helpless. They wouldn't last long on their own.

3's hand writhed under hers, and she could hear his eyes flickering in a frenzy.

"Sh…" She whispered, trying not to sound nervous, "It'll find us."

He didn't stop. In fact, her warning almost seemed to make him communicate louder. She turned and looked at him, watching the flash of lights to try and translate what he was saying. Twin-speak wasn't something that she understood all the way, but she could comprehend some of the words the two of them would say to each other. The only thing she could catch in his flurry of speech was a distinct emphasis on four elongated bursts of illumination.

It was then she noticed that the space next to 3 where his twin should have been was empty.

"4!" She gasped, "Where's 4!?"

How had she lost track of her!? They had been together when they ran from the turret. She had instructed them all to hold hands to keep from being separated, and the twins hadn't protested. That was the last instance that 7 remembered seeing the missing stitchpunk. She hadn't taken the time to make sure that they had all reached the post. Blast it, why hadn't she checked as soon they were safe? Did 4 disappear before or after that? Well, if she had been gone earlier, 3 would've told 7 then. Right?

Or had he been trying to tell her for a long time, and she hadn't been paying attention?

It didn't matter. All that mattered now was finding 4 before something else did. Scanning the area that lay in in front of her, 7 narrowed her eyes, looking everywhere for the bluish-gray form. Nothing. To be thorough she ran through one more time. She couldn't afford to make a mistake. Again, nothing. She looked back at 3, who was staring at his empty hand in disbelief. The hand that had let go of his twin. 7 wanted to pat him on the back, tell him it would be alright, but she didn't know that if that was true. It hadn't been alright for 5 or 6…

There was only one place left to look within the security of their post. Slowly, she turned around to search the expanse on the other side of the wooden stake.

Just in time to see the machine snatch up 4 from off of the dusty ground.

7 froze. No, no! It couldn't be too late! And yet there the missing twin was, dangling upside down in the clutches of the machine, mere meters away from the post where she was supposed to be. Where 7 was supposed to have brought her. Another member of her family that she wouldn't be able to save. A sob caught in her throat, and if she had been able to produce tears she knew they would be running down her face. Not again. Not again.

Time seemed to go slower as the mechanical arm brought 4 closer to its midsection. To the talisman. Seconds lasted for hours, crawling past painfully. 4 didn't even seem to fight back, as if overcome with shock. And fear. All 7 could do was watch in horror. And hold back 3. He was struggling in her grasp, kicking against her. Trying to get to his twin. To rescue her. His eyes were flickering with anger and grief as he nearly exhausted himself doing so.

The talisman hummed with life and shot out the green light, just as it had before. The faces of previous victims unwillingly appeared in 7's mind. 2. 8. 5. 6. And now…4. 7 had enough common sense to turn her head as the light struck and to cover 3's eyes. That didn't stop them from hearing the burning as the soul was wrenched out. Then everything was still. Like nothing at all had happened.

When she looked back the machine dropped the lifeless ragdoll back where it found her, sparking with its newly received energy.

7 couldn't take it anymore. She tugged at 3, trying to pull him back to the post. She didn't want to have to look at the body, forced to remember what she had let happen. Monster. That thing was a monster. Once they found a way, she was going to kill it. No matter what 6 or 9 would say about it. It had to be destroyed. She wouldn't let it take anyone away from her again. Wouldn't let it hurt her.

3 wouldn't come with her. As she took one step back, he dug his own feet into the ground. He was pushing against her hold, trying to get her hand off of his arm, though not as desperately as before.

"C'mon, 3." She begged, "Please. Or it'll get us too."

3 made a strange noise and shook his head. 7 blinked, unsure if she heard correctly. It sounded like…

"C'mon!" She said again, jerking him back towards her. She didn't want to be rough or insensitive, but she also didn't want to lose him too. He didn't seem to understand this. She had to let him know how serious this was.

"…no…"

7 blinked again. "What did you…?"

"No." 3 repeated. This time 7 was watching him more closely. The voice definitely was coming from his mouth. It was no illusion.

3 was talking.

"3…" 7 tried to say something intelligible, but her mouth just ended hanging open. 3 was talking! That and the fact that 4 had just died was making her mind spin into a dizzying land of confusion. Maybe that was it. Maybe the grief was making her imagine things. But his mouth had been moving…

"No!!" he cried, shoving even harder against her. If their squabble hadn't caught the attention of the machine before, it had to of now. It turned its murderous red eye their way, seeking its new targets.

"Please 3! Please!" 7 pleaded, "She wouldn't have wanted this!"

"You don't understand, 7!" He shouted, "We promised!! We promised we would always be together!"

Always. The words stung as 7 understood what he meant. He didn't want to break his promise, but he also didn't want to be alone. Being with 7 wouldn't be the same as being with his twin. As long as the other part of him was gone, he wanted nothing to do with this existence. He wasn't going to let 7 keep him here.

She made it easier for the both of them. She released his arm.

Then she turned, making her way back to safety as 3 ran toward the machine, screaming his twin's name for the first time in his life.

I must thank my little brother wholeheartedly for this plot bunny. Before we had seen the movie we were making lists of who we thought were going to die. I had everyone right except 6 (DARN IT!). He said that he thought one of the twins would die. Then he went on to say that once one of them was gone, the other would be able to talk. When I asked why, he said something on the lines of 'the twins don't talk because they have each other and all they need is to communicate with each other. When one is gone then they need to talk' It doesn't make much sense XD but it sounds deep and I'm proud of my brother for thinking of it on his own. It surely explains a possibility of why they can't speak (as 2 was able to fix that issue with 9 at the start).