A/N: Drabble request by a sweet anon on Tumblr, asking for hallucinating Cas and angry Balthazar (I love protective Balthazar fics!)

Setting: S6, AU version where the Winchesters are helping Cas in the angel civil war instead of Crowley.

Summary: When Cas is injured by another angel, he needs immediate help, but the Winchesters don't have any way to heal him. But they know an angel who does, probably the only one they can still trust.

Poison

"Where is he?" Dean demanded. Both hands raked through his hair. "It's been-"

"Two minutes," Sam cut over him, standing at the panic room door, looking inside with a furrowed brow and tight jaw.

"Long enough to fly his ass down here! The dick isn't gonna show, is he?"

"I'll try praying again-"

Wingbeats fluttered into the confined area of Bobby's basement, bringing an angel to a stop so close to Dean that he nearly collided.

"What," an accented voice gritted out, "gave you the impression I was at your beck and call?"

"Balthazar-"

"Let me make this crystal clear: I don't work for you. Now don't bother me again."

He cocked his head in a sarcastic nod and turned, but Dean grabbed him by the arm.

"It's Cas," he said, ignoring the livid look Balthazar was shooting at the hand on his arm. "He needs help."

"So… help him," Balthazar snapped while brushing Dean's hand away. "Why, where is he?"

Sam and Dean traded a look, then Dean stormed back to the panic room door and wrenched it open with a nod of invitation.

Still shooting him annoyed looks, Balthazar stepped to the threshold and glanced in; immediately, his face went blank.

"No! Don't… don't!" Cas flung his arms up to shield himself, tucked back in the tightest corner of the room with his knees pulled up to his chest. With his head ducked, they couldn't see his face, but Dean already had the image etched in his brain: absolute terror.

"What-" Balthazar started, but fell silent as Cas scrambled from his corner, pulling himself along the floor towards the desk and pressing behind it instead. The concrete floor he'd crossed was streaked with blood from the leg he dragged behind him. Balthazar cursed.

"Stay away from me!" Cas pleaded, voice wavering. "Please- NO! No, stop!" The cry of pain ripped from his throat left Dean unable to breathe.

"We can't get close," Sam explained. "He's hallucinating or something. He thinks he's been captured."

"So you locked him up? Oh, brilliant, you are. You know, if I'd known you two were going to be this piss-poor at taking care of him-"

"You know what?" Dean snarled. "At least we've been trying to help with this Raphael thing, where have you been?"

"Guys!" Sam shouted, shoving his way in front of Dean so he could gesture towards Cas. "We can argue later! Balthazar, you're the only angel we can trust. Cas talks about how close you two used to be. Please, if that ever meant anything to you, will you help him?"

"Of course I'll help him!" Balthazar shot back. "What do I bloody look like? How did this happen?"

Dean ran another hand through his hair, taking a deep, steadying breath. "An angel. I think there was something on the blade they stabbed him with. Cas grabbed us and flew us back here, then he started flipping out."

"He, um…" Sam cleared his throat, eyes damp. "He sounds like someone's torturing him."

Balthazar frowned and he flew inside, squatting down beside Cas and putting a hand on his shoulder. Immediately, Cas's head whipped up, eyes blowing wide in terror as he thrashed to get away.

"No, please! Please, stop-" He broke off with another blood-chilling cry of agony that left Dean's heart breaking a little more.

"Castiel!" Balthazar called over him, which only sent the angel into more of a panic.

"NO! NO!"

"Damn it, there was Hellhound blood on the blade," Balthazar snarled.

Dean's mouth went dry. "Hellhound blood, what does that do?"

"THIS, dumbass! He thinks we're demons and he's in Hell. Once it finishes spreading through his system, it could leave his mind trapped there forever. Eternal torture."

No, no, no… Dean shook his head in denial as Sam gasped,

"Can you heal him?"

Balthazar's face was set in a grim line as he gritted out, "I need you to hold him down. This won't be pleasant."

Though it went against every instinct, Dean hurried to kneel over Cas with Sam right behind, taking a shoulder each to restrain him. When Cas's terrified eyes whipped between them, his breaths coming out as strangled sobs, Dean almost broke.

"Please, no more…" Cas whispered. "Please…" He tried to scramble back, but the brothers held him down—further proof how weakened he was from the poison.

"Here we go," Balthazar muttered as he held a glowing hand over the stab wound in Cas's thigh.

The howl of pain and fear was devastating, but Dean couldn't tear his eyes away as he saw black sludge start to leak out of the wound as Balthazar drew it from Cas's blood. He had to hold on as tightly as he could, watching Cas's body illuminate from Balthazar's power. They could see his veins, dark with poison but lightening more and more as the venom was pulled away.

It seemed to take forever, with Cas thrashing and crying out the entire time, but finally the blackness disappeared.

"Got it!" Balthazar pulled his hand away and the glow died down. The puddle of the Hellhound blood bubbled and hissed on the floor, eventually evaporating away while Cas slumped into an unmoving heap. Balthazar gestured for the Winchesters to let go, then carefully scooped Cas up to lay him on the bed.

"Will he be alright?" Sam asked softly.

Balthazar inhaled, all three of them looking down at the unconscious Cas. "Let him sleep. Raphael won't beat him that easy."

"Thank you," Dean whispered, still shaken as he sat next to Cas.

"You wanna thank me, do a better job protecting him."

Dean didn't even bother to retort, hearing the layer of worry beneath the ire. He turned, wanting to say more, but Balthazar was gone. At least he'd helped, though. Dean took Cas's chilled hand, expression tight. Balthazar was right… they'd have to protect him better.

They were all each other had. Raphael couldn't take that away.