This was Inspired by Not a Chance by Skidzz DevArt. It got crossposted here, at AO3 (which I have now and I'm slowly importing everything from here to there) and at my fanfic tumblr (iwriteinahaze). I wrote this in just about two hours, and my Beta seems to have fallen off the face of the earth, so if you notice any mistakes or typos, all of that blame lands on me.
This is an alternate version of Terra running away from the Titans; instead of letting Slade hack into the tower and trying to rescue Beast Boy, there's a different plan that Beast Boy stumbles into.
'This wasn't supposed to happen', Beast Boy thinks as he takes off running down the tunnel, 'It was just supposed to be a cave in, they were supposed to get some miners to safety, not this.' He can't hear Robin, Raven, or Cyborg, only Terra's gasping pants behind him and the banging footsteps of Slade's robots that were waiting behind the cave-in. He nearly falls as he stumbles over a rock jutting out of the ground, but Terra catches up to him as he staggers against the side, and yanks on his arm.
"Beast Boy, come on! They're catching up to us!" 'They' being Slade's robot minions, whose metallic footsteps echo off the walls as Terra and Beast Boy begin to run again. The same robots that were waiting for the Titans behind the mass of boulders and grit, not the missing miners, that caused Beast Boy and Terra to get separated. 'Did we ever figure out where the miners were? Are the rest of the Titans still okay?' The thoughts don't get vocalized, as Beast Boy morphs into a cheetah and Terra levitates herself on part of the floor, leaving a sizable gap in the ground. "There," she shouts down to him, "That should slow them down!"
Her elation doesn't last long; they soon reach a dead end, and Beast Boy morphs back as they do. Terra runs up to the rock face, pressing her hands against the wall. Her eyes close and her hands glow briefly, before she opens her eyes and whispers, "Nothing." Turning to Beast Boy she adds, "There's nothing I can reach."
"So we can go back the way we came, get to Robin and the others, or sit here. Are those our options?" His frustration and fear bleeds through, and Terra shakes her head.
"We were pretty far underground when we found Slade's robots, running away from them led us further underground. There aren't any neighboring tunnels and-and-" She stutters to a stop as they both begin to hear the faint drumming of the robot's stomping. "Oh, God…"
"Is there anything you can do?" Beast Boy shouts desperately, scanning the walls for anything they might have missed.
"I don't-Wait!" Terra throws her hands in front of her, her eyes and hands glowing. With a grunt and a shout, she raises her arms up over her head. As she does so, the floor in front of her rumbles, then slides up to the top of the tunnel, effectively sealing the minions out…but locking Beast Boy and Terra in.
Beast Boy pulls an emergency glow wand from one of the compartments on his belt, after he's cracked and shaken it active, he begins to scan the walls again. "What are you looking for?" Terra asks, walking over to him.
"Before you blocked off the tunnel, I thought I saw something…There!" he shouts, pointing to a seam in the wall.
"Uh…Beast Boy? I don't think-"
"It's not like the other cracks, it's too regular, too…I don't know, it looks like someone carved it that way." He turns around to look at Terra, whose eyes have gone wide. "It's like someone has a door there or something." Terra nods, but doesn't pull her gaze from the crack in the wall. "Terra? You okay?"
She looks at him, then back at the crack, and shakes her head. "No, I-I'm so sorry Beast Boy."
"For what Terra? You didn't know this was going to happen, no one did."
"Actually-" and as she finishes her sentence Beast Boy hears the rocks grating against each other and metallic footsteps he hates so much "-I did."
Realization dawns, and Beast Boy begins to plead with her."Terra, no, you didn't! Tell me you didn't!"
"Yes, she did."
Terra begins to shake as Slade walks into the room, keeping eye contact with Beast Boy. "I'm so sorry Beast Boy, I was trying to protect you, I didn't realize where this tunnel led until just a few second ago-"
"Silence, girl." Terra closes her mouth so fast Beast Boy can hear her teeth clack together, and they both wince. "There's no sense in lying to him, you knew what you were doing."
"Leave her alone!" Beast Boy yells, surprising everyone in the room, including himself. He pushes Terra against the wall, and as she slides down to the floor, he kneels in front of her, protectively putting a hand on either side of her head. He doesn't want to turn to face Slade yet, he doesn't want to lose his nerve, so he closes his eyes and shouts "What are you doing here?"
"I'm collecting what's mine." Slade's footsteps come closer, and his tone of voice turns bitter. "There are things she needs that you can't give her."
"We can give her all the help she needs!" He doesn't understand why Terra hasn't tried to knock Slade down or away, or why he hasn't morphed into something that could kick Slade's ass. However, Slade hasn't made a move yet either…so he'll try keeping him busy until help comes, or until Beast Boy can make a plan. "She doesn't need you!"
"Interesting…she told me something similar about the Teen Titans." The way he says the team name-no, his team name makes Beast Boy's blood boil, and he finally turns his head.
"Not. A. Chance. She would never say that about m-about us! She knows what you are, and what you are is-!"
"Beast Boy." He turns back to look at her, his angry displaced by her pitiful whisper. "Just-just stop. Please."
"Terra, he is telling lies about us! You can't just-!"
"He isn't lying." When she looks back up at him, he can see how close she is to crying. "I'm sorry, but he said he could help me, and I told him-I told him I didn't think you and the others could. And he- he's already helped me so much." When she blushes and looks down, Beast Boy stands and backs away from her.
"Terra, tell me this is a lie, please." He isn't ashamed to beg, not for her. There isn't anything he wants more than for this to be a lie, but-
"Enough of this. Apprentice." When she jumps up to stand after just one word from that man, that villain, Beast Boy knows Terra is a lost cause. "We have much to do."
Beast Boy watches Terra walk out, and close up the room again, leaving that stupid, perfect crack in the wall. He doesn't bother begging, he just sits where she did in silence.
By the time the Titans have found him, nearly half an hour has gone by and blood has dripped from a scrape over his forehead and onto his cheek, but he can't bring himself to wipe it away.