The slap resounds throughout the whole cave. The bats fly off, disturbed, chittering. Tim drops his mug.

The crash of the mug does little to disturb Bruce, whose eyes flicker to where Tim is, on the opposite side of the cave, analysing a blood splatter pattern for a recent case, before surveying Dick, who is panting, head turned away from the slap. Tim can just make out the red outline of a handprint on his face.

"Right." Dick speaks, voice raw, even though he had barely raised his voice before being slapped. "That's how it is."

Bruce crosses his arms, cape sealing around him, shadows wrapping around him like shock is wrapping around Tim, clouding his mind, clogging his veins. Because, what? Did Bruce just hit Dick? Tim may not be Jason, but even he could tell that Bruce seemed to favour Dick above them all. Well, okay, this may have changed his mind a little.

Tim dared not move closer, but he strained his ears to listen in.

"You were irresponsible tonight Dick." Bruce growled.

Dick let out a tired laugh, and scrubbed at his face, the remnants of the glue from his mask peeling off like dead skin cells, "You say that every night Bruce."

"You disobeyed my direct orders and nearly jeopardised the entire mission. The mission we have been working on for months now!"

Frustration bled out into Dick's voice, "The mission? That's all you care about? Not Jason nearly taking a bullet to the shoulder?"

Bruce just gritted his teeth. Tim bit his lip. Sure, it was no secret that Bruce and Jason weren't exactly on the best of terms, but generally Bruce cared about all of his children's wellbeing. Right? Right?

Tim's anxious spiral nearly caused him to miss Dick's next words, low and quiet. "God Bruce. You could at least try to pretend to care."

Bruce's fists began to clench, a sure sign that he was getting ready to throw a punch. Tim's stomach clenched, knotting, anxious as Dick continued, "You know, I try, try so damn hard to tell the kids you care about them, that you love them, that you would go to the ends of the earth for any of them, even Jay and Dami. But God, would it kill you once in a while to prove that?"

Tim started to make his way over to them, watching as Bruce's anger climb, his jaw work, wondering where the hell everyone else was in this godforsaken family was, readying himself to intervene should it come to it.

"The mission-" Bruce started, a vein pulsing at his temple-

"Forget the fucking mission Bruce! Can you just try to be a good father to them!" Dick threw his hands up in anger.

Tim saw the punch before it came, saw every move telegraphed in horrifying slow motion. Bruce, pulling back his right arm, leaning on his back leg, following through with a right hook, and punching Dick squarely in the jaw with zero hesitation, nearly full strength, messy, uncoordinated, not at all like the cold, clean and efficient methods of Batman; no this was all Bruce, Bruce's rage, Bruce's anger.

Dick was knocked to the ground immediately, and before he knew it, Tim had run forward, disarming Bruce, sending him crashing to the floor, the element of surprise on his side as evidenced by the bare shock in Bruce's eyes.

"Tim-" Dick started, behind him on the floor, voice thick with an emotion Tim couldn't quite identify.

"What the hell was that Bruce?" Tim hissed out, bo staff extended, pressing down on his chest.

"Tim please-" Bruce raised his hands in a placating manner, expression softening as he looked up at Tim, "Let me up, this is just a simple argument-" But no, no it wasn't, Tim thought, feeling the adrenaline course through his veins, his brain replaying the hit over, and over and over again, in bright, 4k technicolour.

"No Bruce," Tim hissed, "That looked like a father hitting his son."

Bruce's face shuttered, "Tim, let me up. This is an argument between two adults-" He said in his Batman's voice, the tone allowing for no argument.

"How long?" Tim turned around, craning his neck at Dick, who had gotten up, looking guilty as he nursed the swiftly developing bruise on his jaw, "How long has this has been going on Dick?"

Dick glanced away, and murmured, "It's fine Tim, leave it alone, I can handle it."

"The hell you can!" Tim exploded, surprising himself.

"Tim," Dick said softly, placing a hand on Tim's shoulder. He hadn't realised he was shaking. "Let him up."

Reluctantly, Tim straightened up, allowing Bruce to gingerly get up. He scowled at the man, crossing his arms.

"Come on Tim." Dick was leading him away, movements non-threatening, in the voice that he usually used with victims. Tim hated it. He should be the one comforting his big brother after this, not the other way round.

"How long Dick?" He said immediately, when they were out of reach of Bruce, safe in the showers. Dick clenched his jaw and looked away. "Dick," Tim pleaded, his voice cracking, "Please."

Dick's face was turned away but his shoulders were tense as he said, "Since before Jason."

Jesus Christ. That was years. Dick would have been Tim's age or younger.

Tim sucked in a breath, "Do the others know?"

"No." Dick's reply was immediate, "And they're not going to."

Tim's mouth fell open in shock. "Dick, what? You have to tell them!"

Dick's fist clenched, "I said no Tim! They can't know. They need..." Dick paused, taking in a shaky breath, Tim's chest ached for Dick. "They need to think he's a good father, okay?"

Tim tilted his head to look at the tiled ceiling, helplessly. Dick had been dealing with this for years and none of them had ever known. The rush of pain and empathy for Dick nearly made Tim buckle to his knees. Instead he sat on the bench and quietly murmured, "And what if it was one of us?" Tim looked up at Dick, whose face held a micro expression of horror.

"He wouldn't." Dick answered, automatically, still determinedly defending Bruce somehow with such conviction that Tim didn't know whether he wanted to laugh or cry.

"You can't know that for sure."

Dick shook his head with a sad smile on his face, "I made sure I took all the hits for you all Babybird."

And God that just made Tim feel a hundred and ten times worse. How many hits had Dick taken for him? Tim could feel himself spiralling, guilt crawling up his throat, but he shook his head, attempting to refocus himself. Now was not the time, he needed to help Dick first, and then take a massive guilt trip later.

"I'm telling the others." Tim said decisively, and Dick's head shot up.

"Tim, no-"

"No Dick," Tim said firmly. "The others need to know. This has gone on for way too long. And I could never forgive myself if you-" Tim broke off his sentence as Bruce's punch replayed once more in his mind, the sound of flesh hitting flesh and the crash of Dick falling to the floor.

He wasn't sure what they'd with (or to) Bruce once the others knew, but he did know this: the batfamily sticks together, and robins don't leave robins left behind.