A/N: Not my usual fandom, but I recently got into watching Shadowhunters and have been really enjoying it. And sometimes it's nice to dabble in new fandoms when trying to kickstart the muse after a dry spell.

Disclaimer: This world and characters aren't mine.

"Famous Last Words"

It'll be a quick mission, he'd said. A chance for them both to get out, blow off some steam. They didn't get the opportunity to go on patrol together very much lately, and Jace said he missed it. So did Alec, which was why he'd agreed. It was just a nest of shax demons. Easy.

Famous last words.

`.`.`.`

"Luke said there have been reports of homeless mundanes going missing in the area," Alec briefed Jace as they headed into a section of old subway tunnels. "Doesn't quite sound like shax demons' MOs."

"Unless they're trying not to draw attention to themselves," Jace replied.

"Since when would they care?"

Jace shrugged, and drew his seraph blade as they approached a juncture leading deeper underground, the adamas briefly flaring azure. "Doesn't really matter, does it? We put a stop to it."

Alec notched an arrow to his bowstring and they strode onto the darkened platform, having already activated their runes for night vision. A bulge in the corner stirred at the change in the air, but Alec loosed his arrow before the demon could even get up. It burst into ash with barely a shriek, but now the rest of the nest was waking. Jace's blade gleamed like heavenly fire as it smote its targets. Alec fired several more arrows before the fighting became too close and he whipped out his own blade.

He and Jace moved in tandem, seraph blades singing and demonic cries crackling into brimstone. It was easy work. Until the ground suddenly shook and a guttural rumble sounded from one of the tunnel shafts. There was only one shax demon left, and it cowered back with a quivering chitter before ducking into a shadow and skittering away. Alec and Jace exchanged a look as another heavy impact shook the walls.

Jace lifted his blade. "What the hell is that?"

Alec didn't know, but he was getting a bad feeling. He switched back to his bow, an arrow nocked and aimed at the darkness. A massive shape came barreling through the opening, hulking frame skimming the ceiling and scraping silt loose. Alec barely had time to home in on a soft target before the demon was upon them.

He fired the arrow at one of the eyes, or what looked like an eye. The demon had broad shoulders and a pudgy face with a row of viscous orbs across a wrinkled forehead. The mouth was wide and full of spicule-like teeth. And though its top half was somewhat upright, its bulging arms hung down to the floor and it moved like an ape.

The beast roared at the arrow striking its head, but didn't lose momentum. Alec and Jace dove out of the way. Alec rolled into a crouch and drew his seraph blade again. He'd lost sight of his parabatai, but the demon jerked around with a howl, snapping at something on his other side. Alec lunged forward, plunging his blade deep into the meat of the demon's leg, then quickly wrenched it back out and spun away.

He didn't have to see Jace to know the plan was to attack the demon on opposite sides, try to keep its attention divided until one of them could get in a killing blow. Alec slashed again. He'd never encountered a demon like this before, and briefly wondered which dimension it was from.

Ichor was beginning to coat the floor, making conditions slightly more hazardous. Where was the damn thing's core?

The brutish beast suddenly threw its head back with a bellow, and Alec caught sight of Jace rolling underneath the demon to thrust his blade up into the chest. The demon wrenched away, crashing into the wall. Alec dove for his brother and grabbed his arm to haul him up before he could get trampled.

The demon continued to twist and rage, slamming itself into the cement. Stone and brick began to trickle down around them. Jace arched his arm back and threw his blade. It whipped end over end through the air before striking true, and the demon fell backward against the wall. Brimstone snaked through the cracks in its flesh as it began to disintegrate, but the impact continued to reverberate through the walls…

Alec grabbed Jace's arm and yanked hard, pushing him toward the exit. And then the ceiling caved in.

`.`.`.`

Alec tried to shift where he was laying flat on his back on the cold hard ground, attempting to alleviate some of the pain in his lower back, but of course it didn't help. His legs were pinned under a slab of concrete and other debris, rendering him immobile. Not that he could go anywhere anyway.

A grunt sounded from his far left, followed by a curse. Alec gathered that Jace's attempts to break through the rubble weren't getting very far. How long had they been trapped down here now? A few hours, at least. Jace's phone had been smashed in the collapse, and Alec's didn't have a signal this far below ground. The only use it was now was sitting out on the floor to emit some light in the otherwise pitch chamber. All in all, things hardly could have gone worse.

"I'm missing my date with Magnus," Alec put out there.

Jace shuffled back into his line of sight, his busted arm tucked inside the fold of his leather jacket to stabilize it. His iratze rune had focused its energies on healing some other injuries, leaving the broken bone as a lower priority. "At least someone will realize we're missing sooner rather than later," he replied.

"I'm telling Magnus this was your idea."

"That's not fair."

Alec snorted. "Better he blame you than me. He's been talking about these reservations for a week. And I've had to reschedule or cut short our last few dates."

Really, Alec should have known better than to take a mission that day.

Jace finally sank to the ground next to him. "Well, I guess as your parabatai, I should be willing to take the hit for you on that." His gaze slid to Alec's trapped legs.

"On that," Alec agreed lightly, but the effect was ruined by a grimace. The pain was increasing in his leg again, but he couldn't tell whether it was just from being pinned, or if there was an injury his iratze hadn't taken care of. There was plenty of demon blood splattered around that might interfere with the healing rune.

Jace was frowning at him. "What is it?"

"I don't know. Maybe a cramp." Or a fire poker.

Jace pulled out his stele. "I should draw another iratze."

Alec lolled his head back and forth in the negative. "I don't think it would help." He winced again at another shooting pain through his calf. If only he could see what the damage was. Was it broken? Cut open and bleeding?

Jace's mouth pressed into a thin line, and he turned his focus to the slab. "I can use a strength rune and lift it. Think you can shimmy out?"

Alec sighed and tried to shake his head again. "Not with that broken arm."

"I'll manage."

Jaw setting decisively, Jace got to his feet and tugged the collar of his shirt down to reach the rune. He was already running his stele over to activate it before Alec could offer up more reasons why it was a bad idea, and then Jace was squatting down to grip the bottom edge of the concrete with his good hand. Alec tensed.

Jace's cheeks puffed with exertion, and he reached out his bad arm to grip the slab as well, grunting in pained effort as he started to lift. Alec propped himself up on his elbows in preparation to move, but as something shifted, pain lanced through his leg like fire. He gritted his teeth against crying out, but the slab hadn't lifted enough for him to move. After another long moment, he couldn't hold it back anymore.

"Agh, Jace, stop! Stop!"

Jace released the concrete and staggered back, and Alec's vision whited out for a moment as the full weight of the debris dropped back onto his legs with such agony that it left him panting. Hands grabbed frantically at his heaving shoulders.

"Alec? Alec! I'm so sorry."

Alec forced himself to breathe in and out until the inferno in his leg receded to a duller burn. "Let's not do that again," he managed between ragged breaths. He suddenly felt a lot colder.

Jace rocked back into a seated position, drawing his knees up. "I'm sorry, Alec," he said, sounding as though he meant more than the failed release attempt.

"Magnus will come looking for us soon," Alec responded. They just needed to wait. Except, he was definitely getting colder; a shiver wracked his frame, jostling his already aching body. Pain shot through his leg again, and he squeezed his eyes shut for a moment. "Jace," he gasped. "My leg…"

A hand gripped his shoulder, and then Jace swore under his breath. "Alec, you're cold. And you're shaking."

Was he? Oh, maybe.

"I'm tired," he murmured, surprised by the admission.

There was shuffling beside him, and then Jace cursed again. "You must be bleeding somewhere. Maybe your leg. Here."

Alec pried his eyes open as Jace yanked his shirt up, stele in hand. Alec felt the heat from the instrument as it traced a rune on his chest near his heart.

"I did an amissio," Jace said. "If the iratze wasn't enough, that should at least slow the blood loss and help replace what you've already lost."

Alec nodded minutely; he already felt a little warmer. Hopefully he wouldn't bleed out before they were found.

He could feel Jace's worry pulsing through their bond as they sat in silence in the dim halo of LED light. How much battery life did his phone have? That was just another potential complication he didn't want to think about. He thought instead of candlelit dinners and glittery cat eyes.

Jace reached out and clasped his hand, and Alec imagined he felt a little more strength cement itself in his bones. The parabatai bond didn't transfer energy, but it was a tether that kept him anchored, even when he felt the amissio start to wane.

He wasn't sure how much more time had passed before a loud boom reverberated through the room. Alec flinched, mind instantly flashing back to the demon, but then he heard a crackle and sizzle, and Jace was jumping to his feet.

"Hello?" he shouted. "Is anyone out there?"

"Jace!"

"Clary!"

There was a whoosh of air and the area around the debris bent and refracted as a portal opened up. Clary came barreling through, along with Izzy and Magnus.

"Alexander!" Magnus swept across the room to drop down beside Alec, one hand reaching out to cup his face.

Alec gave the warlock a weak smile. "Hey," he rasped.

Magnus returned the smile, though his eyes were clearly worried.

"It was Jace's fault," Alec felt obliged to add.

"Personally, I'd blame the thirteen-foot demon," Jace put in as he, Clary, and Izzy came over.

"You said you were hunting shax," Izzy accused.

"We did. They were just apparently nesting with something else," Alec wheezed.

"Oh god, can we get him out?" Clary asked, getting straight to the matter at hand as she surveyed Alec's predicament.

"That, I can handle," Magnus replied. He gave Alec another small smile and ran his thumb across Alec's cheek before pulling away and standing up to face the rubble. Blue fire erupted from his fingertips as he swept his hands back and forth, then shot out to envelope the debris.

Alec tensed, and clenched his jaw as the concrete slab was lifted and pain exploded in his leg anew. Magnus raised the rubble and tossed it several feet away. He then dropped down to one knee and immediately began waving his hands over Alec's legs. Wisps of magic flowed down and swirled around him before penetrating his flesh down to muscle and bone. Magnus's healing had a sharp fizzling sensation at first, but always melted into a warm and soothing balm. Alec's tension eased under the touch.

Magnus sucked in a sharp breath. "Compartment syndrome."

Alec tried to lift his head to look, but couldn't see much. "What's that?"

"Pressure buildup from bleeding internally," Izzy supplied with a trace of concern. "Can you heal it all?"

"Almost done," Magnus answered, and his voice had a touch of his normal cheer again. Alec relaxed.

The glow of magic receded, along with the warmth, but Alec didn't feel cold in its absence. A bit worn out, but otherwise fine. He started to sit up. Magnus and Jace each surged forward to help. They pulled him to his feet, and man did it feel good to be upright again.

"Are you okay?" Izzy asked.

Alec nodded. "I'm fine now." He flashed Magnus another smile. "Thanks."

"Jace, are you okay?" Clary asked.

"Nothing another iratze won't fix when we get back to the Institute," he replied.

"His arm's still fractured," Alec interjected, and flicked a requesting look at his boyfriend.

Magnus's eyes softened with understanding, and he gestured to Jace. "Allow me."

Jace hesitated for only a beat before holding his arm out, and a blue aura once again filled the dim tunnel as Magnus's magic swirled around the limb. The warlock snapped his hands back with a flourish, extinguishing the magic.

"Now then, can we get out of this dismal place?"

"Fine by me," Jace muttered.

Clary's mouth curved upward wryly, and she pulled out her stele to draw a portal rune in the air while Izzy went and picked up Alec's and Jace's weapons left lying around. Golden light spilled forth as time and space folded into a spiral.

Alec snagged Magnus's sleeve as the others started toward the dimensional door that had opened up. "I'm sorry about the reservations. I'll make it up to you."

Magnus canted his head with a small twitch of his lips, and he reached out to cup the side of Alec's face again. "I'm just glad you're all right. But I do look forward to you making it up to me."

Alec furrowed his brow. "Why do I get the feeling you enjoy me having to make things up to you?"

Magnus flicked his hand dismissively. "I have no idea what you're talking about." But there was a sly twinkle in his eye.

Alec shook his head in fond amusement. "One of these days we'll have a normal date night without shadowhunter or downworlder business interrupting."

Magnus grinned. "Hm, famous last words."