Don is usually pretty good at remembering that no location is truly safe, but sometimes being in the spaces that he considers to be his little brother's—the garage, CalSci, and in a weird way now, the War Room—he lets his guard down and forgets that even those places can be made dangerous.

So when an explosion rocks the Physics department at CalSci, hurling him to the floor in a shower of broken glass on his way to see Charlie, he's stunned. Not just surprised the way he would have been if the explosion had occurred on some random L.A. street corner, but absolutely stunned to the point where he lies on the floor, blinking up at the cracked and smoke shrouded ceiling until the smoke isn't gray, but black. Then, finally, the FBI agent in him wakes up, cramming the part of him that believes in safety in a nearby locker and slamming the door.

The first thing Don notices as he drags away the shock like a tattered old sweatshirt is that he's soaking wet. Overhead, the sprinklers are blasting away. The water is dirty and smells like mold and mildew and disuse and he grimaces because it's turning his shirt a nasty shade of brownish-yellow and that's just gross.

The next thing he registers is the sounds of screaming and crying, alarms; panic. But just as soon as he's noticed all of that, it disappears, overwhelmed by the deafening ringing in his ears because he's just sat up and the blood is rushing away from his head to flood to the spot on his right hip where there's a six-inch long jagged hunk of metal jutting out of a slowly darkening slash in his jeans. Dammit.

He's not sure how, but he manages not to pass out and he's sitting there staring at the metal in his leg, dirty water pouring down on his head, when he suddenly remembers why he was here in the first place.

Charlie.

Charlie in Larry's office helping with the calculations for some kind of solar radiation burst thing and dammit he needs to get up now.

That's not as easy as it sounds and his vision whites out at least once while he's dragging himself to his feet with the help of the wall and the display case attached to it.

When Don is finally upright, he leans against the wall, grimacing at the pain along his hip, searing and throbbing at the same time. Between each pulse of the wound he can feel the trickle of hot blood along his thigh, inside his jeans. He takes a few panting breaths, thinks of Charlie, and pushes himself forward.

There are at least four inches of standing murky brown water in the hallway now, but Don sloshes on despite it, limping and hissing with every step because that hunk of metal really doesn't approve.

Part of him wants to go and figure out what the hell happened, why there was an explosion at CalSci of all places, but his brain feels like scrambled eggs and his firearm is at home because for once he's got a day off and a gun wasn't supposed to be a part of the picture.

That, and there's another, larger part of him that's scared to hell about what could have happened to Charlie.

He shuffle-limps faster, panting against the pain and the exertion and the adrenaline pumping through him like jet fuel and reaches the door to Larry's office just a few moments later.

Relief hits him like a shock wave, so strong it nearly buckles his knees.

Charlie is there, bent over Larry's desk muttering frantically to himself and scribbling in a notebook despite the water pounding down on his back, his hair so soaked it's almost straight. Larry is nowhere to be found.

"Charlie!" Don croaks out and shuffle-hops into the room, gritting his teeth because the pain in the wound on his hip is heating up, burning from the inside.

He gets no reply, just more muttering and more writing and Don starts to freak out a little. Charlie isn't just leaned over the desk, he's leaned into it, his entire upper body practically sprawled on top of it, supported by his elbows, his head curved down to complete the arch of his back. He sounds almost insensate. God, what if—

"Charlie!" he says again and this time his voice is a little stronger, sharpened by his concern. He makes it to the desk, kind of slamming into it with his uninjured hip, using it to take some of his weight off of his jellied knees. He bends forward, supporting himself on one elbow like Charlie and uses the other hand to reach for his brother's shoulder. "Charlie. Charlie, are you okay?"

He glances up, eyes wild, and says, "The sprinklers. The sprinklers went off and the chalkboard it's washing all of my work away—"

"Charlie!" Don says, raising his voice, "Are you okay?"

"What? Yeah, no," Charlie says, already distracted with his eyes jumping between the melting figures on the chalkboard and the notebook he's attempting to protect with his body, for all the good it's doing. "No, I'm fine, I just— These figures—"

"Dammit, Charlie, something just exploded here, okay? Do you think you can focus for two seconds so I can make sure you're not hurt?" Don sounds even more pissed than he meant to because he's breathing through his teeth. His leg is really starting to hurt.

Charlie stops writing and looks up again, his eyes wide. "That was really an explosion? I just thought—"

"No, it was really an explosion. Now are you hurt?"

His head shakes, wet curls slapping lethargically against his cheeks, his mouth open. "Oh my god. I just, you know, assumed it was some kind of experiment or something gone a little awry. An earthquake. A—a— I don't know. Something else." He waves the hand with the pen at the front of the room and says, "I slipped and fell when the sprinklers came on, but I don't even know if there's a bruise. I—"

Halfway through Charlie's babbled explanations, Don's remaining strength dwindles out of him and despite his attempts to hold onto the desk, his muscles just stop working and he slides to the floor, doing his best to stifle a cry. That's easier said than done because the fire in his hip is spreading and it feels like he's been nailed in the crotch, his entire leg filled with bolts of electric agony.

Finally, he opens his eyes. There are tears in his eyelashes—at least, they burn like tears—and Charlie's face is so close he starts to get claustrophobic.

But Charlie's eyes are as wide as he's ever seen them, his face blanched white, and he looks like he might be crying. The water dripping down his face makes it hard to tell.

"It's okay, Charlie," he says, but Charlie just looks more terrified.

"Don," he rasps, voice a whisper, "There's someone out there with a gun."

"What?" Don says. He tries to sit up and meets resistance in the form of Charlie's hand against his sternum.

"Don, don't get up. Y-you're hurt. Your leg—" He swallows and then says, "I can't believe you were walking around. And you were worried about me?" He tries to smile, but can't quite manage.

Then Don hears what sounds like two gunshots from down the hall.

Charlie's glance toward the door confirms that the sounds are coming from inside the building, the remaining color in his face washing out in a rush. "Don—" he whispers and this time that droplet is definitely coming out of his eye.

Don pushes himself up, despite Charlie's hand and his brother stutters out protests even as he drops his head to try and conceal his fear. Don shuts him off with a sharp, "Charlie!"

His eyes are huge, liquid. "Y-yeah, Don?"

He puts pressure on Charlie's shoulder, gentle, nudging him back and says, "I need you to get under the desk, Buddy."

"What?" he says, bewildered.

Two more shots go off in the hall, closer now, and Charlie freezes up.

"Get under the desk now, Charlie," Don orders, shoving him. Finally his brother does as asked, moving back behind the desk, slipping and sliding like he can't get control of his limbs. He stops near the hollow beneath the desk and asks shakily, "W-what about you, Don? I don't—"

Don pushes him again. "Just get under the desk, Charlie."

The sprinklers shut off abruptly and the room goes quiet, allowing Don to hear the sound of someone sloshing toward them down the hallway. His heart starts to pound. "Stay quiet," he orders Charlie in a fierce whisper and his expression goes a little frantic.

"Wait, no, Don—Don, what about you—"

Don glowers at him, putting a finger to his lips before dragging himself toward the far end of the desk, just around the corner. No way in hell he's letting anything happen to Charlie, so he needs to be able to get out in the open, fast, if the perp starts snooping around.

"Don!"

"Shut up, Charlie!" he hisses and in the silence that follows, listens intently to the sound of the perp's sloshing footsteps.

Don can hear Charlie's fast, shallow breaths when the perp stops in the doorway and his muscles feel like wires wound too tight, ready to snap at the slightest provocation. After what feels like ten thousand years, the perp moves again, Don primed to throw himself out into the room, but the sloshing is headed away from them, further down the hall. Don doesn't move until the quiet sound of wading is almost indiscernible.

"Where's Larry?" he asks then, keeping his voice low, just in case.

"He—he went to go get us something to eat, just before the—"

"Good," Don says. The room is starting to spin like he's gotten on a carousel and his stomach churns when Charlie's head peeks out from around the corner of the desk, lines of worry drawn in between his eyebrows, around his mouth. Alarm flashes onto his face and Don turns his head, trying to find the source of the reaction. "What is it, Charlie? What's wrong?"

"You don't look good, Don. You—you—"

"Well, I feel like shit," Don says and closes his eyes. He can't find anything.

~ * ~

Don feels good.

Really good. The drugs the doctor has prescribed for him are working miracles. His hip aches a little, but even so, he feels good. Combined with the food their Dad has laid out on the table, things could be a hell of a lot worse. He's always happy when there's steak involved.

As Dad pulls up his chair and sits down, he says, "Okay. I'm ready. Explain what happened at school today."

Don's face pulls into a lazy grin and he looks over at Charlie to see him smiling too. "I feel like I'm in fifth grade again, Dad."

"When you were in fifth grade you came home with a rusty nail in your hand. This is not so different."

Charlie's grin broadened. "He has a point."

"Shut up, Chuck. You weren't even born yet."

That immediately wipes Charlie's smile away. "How many times do I have to tell you not to call me that?"

"You like it. Just admit it, Chuck. You do."

"That is completely—"

"Boys!" Dad barks, glaring at them both. "The story? Maybe before I die, if you don't mind?"

Charlie is still glaring, but Don moves on easily because he knows it bugs his brother to leave an argument unfinished. "There was an explosion in the Physics department at CalSci."

Their dad nods. "I heard that much on the news."

"Yeah, something explodes a couple doors down and Charlie's still in Larry's office worrying about his chalkboards." He smirks at his brother and Charlie spreads his hands, incredulous.

"They were important equations! Larry and I spent all morning working on that hypothesis!"

Dad gives him a look. "It's times like these I'm grateful you're not more involved in your brother's work. You know, most people hear an explosion and they exit the building."

"It's the physics department!" Charlie protests, waving his fork. "There are explosions all the time!"

Another look from their father. "That is not exactly reassuring."

Charlie gestures at Don and Don realizes as he's opening his mouth that he's about to get his turn in the hot seat. "At least I'm not like Don, walking around with a huge hunk of metal in my leg!"

Their father nods. "This is true."

"I was only walking because I had to find you and make sure you weren't doing exactly what you were doing—not leaving the building." He takes a bite of the steak and immediately reacts with a fervent, "Mm, Dad, this is great."

He smiles. "Thank you, Donny. I'm glad you like it. Even if it's not a surprise."

"Anyway," Don says, after taking another bite, "The explosion was set off by some student. We don't really know what happened. Seems like he just lost it. There were a lot of injuries, a couple of gunshot wounds from his little shooting spree, but fortunately everybody made it out alive." He shakes his head. "Nuts."

"I'm just glad he didn't get anywhere near you boys," their father says and Charlie glances up at Don, sharing a look with him while their dad cuts another piece of steak.

"Yeah, we're glad he didn't, too," Don says, turning back to his dinner.

For a few minutes, they eat quietly, forks and knives chinking against the dishes. Now that Don is thinking about the day again, he can't believe how unprepared he was. He shakes his head and says, "You know, I think today was the most shock I've had to deal with in...I don't know, forever. Explosions while I'm at work, that's expected. But at CalSci..." He shakes his head again. "I don't know. It threw me off."

Charlie looks at him, a marveling expression on his face. "I don't know how you can say that. How can an explosion not be shocking?"

Don shrugs. "I don't know, Charlie. It's just par for the course in my line of work. I expect the unexpected." He points his fork at his brother. "But apparently not at CalSci."

"Well, you shouldn't have to expect explosions when you're visiting me at work, Don," Charlie says.

"Apparently I should," Don points out. "You do."

Charlie opens his mouth to refute this and his hand twists in the air, but his head tilts to the side. "...that's not the same, and you know it."

Don smirks. "It's okay. Getting a little shock every once in awhile isn't necessarily a bad thing. It means I'm still, you know, connected."

Charlie and his dad just smile.