***A/N***

Another Douglas Adams prompt...

"If there's anything more important than my ego around, I want it caught and shot now." -Douglas Adams, "The Hitchhiker's Guide to the Galaxy"

"John! Excellent, you got my message." Sherlock yanked the goggles from his head, tossed them on the table, shoved something into the pocket of his robe and swooped into the sitting room. The excitement with which he descended upon his flatmate, relieving him of the carrier bag stuffed full with Chinese takeaway and his coat in only a few quick movements left John feeling dizzy, and a bit giddy.

"Solved it, then?" John laughed as Sherlock guided him to his chair and made him sit. "Have to admit, after the interviews with the suspect today, I was surprised you requested dinner."

Sherlock waved his hand dismissively and swanned back into the kitchen. "I knew the who, the when, and why almost immediately." He returned with plates, two tumblers, and the good Port Greg had given John for his birthday. "It's the how and with what that has been problematic. Until now." He sat dramatically in his chair, eyes flashing with glee.

"So the substance you found, that powder, you identified it?" John smiled as he handed Sherlock a carton and a set of chopsticks.

"No." Clearing his throat, Sherlock set his food aside and accepted the tumbler John passed to him.

"No?"

"No." Sherlock took a sip of his drink. "That is to say, not yet. I believe one more test will suffice."

"Well, I'm happy to help if you think I won't make too much of a mess of it."

"I was hoping you would offer. I can always use your medical opinion."

John smiled again, then closed his eyes and sighed as he took his first drink. "That's good." He shivered, and only then noticed the windows were slightly open allowing the damp autumn air in.

"You're chilled. Let me build up the fire." Sherlock stood, patting John's knee as he did so, and turned to tend the fire.

"I could just close the windows. Why are they open, anyway?" John moved to stand, but Sherlock stayed him with a hand on his shoulder.

"You wanted to assist me with my experiment." Sherlock gazed into John's eyes, a tremulous, hopeful smile playing at his lips.

"Oh christ. Have you poisoned me? Again?" He shrugged Sherlock's hand off his shoulder and glared into his tumbler.

"I swear to you, you have not ingested anything deadly. If you recall, you retrieved the food, and you opened the bottle." Sherlock still hovered over John, with mischief in his eyes.

"But?"

"You have a matter of seconds to leave now if you no longer wish to assist me." Sherlock dropped back into his chair and picked up his drink. He pulled a small packet from his pocket.

"Is that?" John leaned forward to get a better look at the tiny envelope Sherlock was flipping between his fingers. He frowned and studied the floor for a moment. "Did you move my chair?"

"This," Sherlock held up the envelope, "is but a fraction of our mystery substance. I believe the deadly hallucinogen was airborne, and delivered in a most obvious manner." They both glanced at the fireplace. Sherlock flicked his wrist, about to toss the packet into the flame.

"Don't!" John put his hands up in a placating gesture. "Bloody hell, Sherlock. Even you can't be foolish enough to believe this is a good plan." He held out his hand.

"There are two of us. A graduate level chemist - a genius - and a physician. The dose is a fraction of the amount used on the victims. I've opened the windows and left the door ajar for ventilation. Our chairs are precisely equidistant from the fireplace, so we'll be exposed equally. If a problem should arise, either one of us can act, pulling the other to safety." Sherlock leaned toward John, neither man budging on his opinion. "Fool proof."

"Hand it over." John's hand remained steady as he waited for Sherlock to give in.

Sherlock rolled his eyes and sighed. Just as he was about to drop the envelope in John's hand, he fumbled it, recovered it, and promptly flipped it onto the fire. "Oops."

"God, I fucking hate you sometimes. I hope you know that." John flopped back in his chair.

"You can still leave." Sherlock watched the envelope burn. "But you might want to hurry."

"You know very well that is never going to happen." John clamped his hands around the ends of his armrests and stared as the unusual colors danced in the flames. "Bastard," he grumbled.

"Faithful, courageous Doctor Watson," Sherlock smirked and raised his glass in a mock toast.

"Piss off." John kept his eyes trained on the fire and breathed deeply through his nose. A musky, slightly spiced scent, faint at first, reached him and he felt his face twitch. There was something familiar… He couldn't place it…

As the heat fully engulfed the envelope there was a bright hot flash and the flames roared in the fireplace. What John saw, as the scent grew stronger, was the flashpoint of an IED. Black smoke edged in eerie blue tones curled around him and he dove to the floor, covering his head with his arms. "Get down! Everybody down!" He choked on the words, even as the feel of carpet instead of sand added to his confusion.

John reached behind him for his kit, but found only his service weapon tucked against the small of his back. He raised himself to a low crouch, his heart racing with fear. There, in front of him. A man. He raised his weapon and tried to identify himself, though he could only gasp for breath, his anxiety quickly growing to terror.

The other man stared straight ahead, straight through John. His face etched in horror, mouth open in a silent scream, and tears ran down from his eyes. Those eyes. John knew those eyes. That face. He'd seen that fear before. Where. Where, damn it?

John swore he heard a low growl. The hound. Oh god. Oh fuck. Sherlock. He forced himself to his feet. They were going to die. His head pounded, he was nauseated, dizzy, and fucking terrified.

"Sher…" John gasped. Sherlock. He had to get him out. Something moved behind Sherlock, and John raised his gun again, taking aim.

Sherlock coughed violently then, and it jarred him enough to notice the gun aimed in his direction. "J- John. John, no!" He put his hands over his head as two shots rang out, shattering the window behind him.

There was a moment of terrible silence before John turned and fired two more, destroying the other window. He tossed the gun to his chair, grabbed Sherlock by his shirt and hauled him from his chair.

"Out. Out now." They crashed to a heap on the landing as John slammed the door behind them.

"Sherlock! What are you two doing up there?" Mrs. Hudson shouted from her doorway. "It's enough to give a person a heart attack."

"Out!" John tried to shout, but mostly coughed, as he took great heaving breaths. "Mrs. Hudson, get outside. Now!" He pulled Sherlock up, and together they stumbled and crashed down the steps.

"Good heavens." Her hands fluttered at her neck.

"Now, woman," Sherlock choked, finally regaining some clarity.

With an indignant huff, Mrs. Hudson snatched her coat from the hook and stormed out the front door. John and Sherlock stumbled out behind her, supporting each other, dragging each other along.

John was frantic, trying unsuccessfully to check Sherlock's pulse with trembling hands. He was mumbling incoherent curses and still gasping for breath.

Sherlock realized, a bit too slowly, John was crying.

He shook his head to try to clear the images that had taken his own mind. John strapped into a bomb. John lit up with laser sights. John dead. Dead. He soon realized he was crying too as he tried to shove John's hands away so he could do his own check to make sure his flatmate was truly alive in front of him.

It took a moment longer to realize he was chanting, "I'msorryI'msorryI'msorry," over and over.

"Never again." John grabbed him hard by the shoulders. "Never do that again."

"Never." Sherlock agreed, closing his hands around John's biceps. "John, I'm sorry. I can't… Just. This was truly unforgivable. But, if you could…"

"Just, swear to me. Never again."

Sherlock nodded, and ducked his head. He continued to mumble apologies.

John shushed him. "Sherlock, stop. Just, close the fucking case, yeah?" He nodded to the police cars that pulled up next to them.

"Right. The case." Sherlock wiped his sleeve across his eyes and offered a tiny sheepish smile. "And John?"

"Hmm?" John scrubbed his hands over his face and cleared his throat.

"Thank you. You saved our lives. Mrs. Hudson too."

"Sherlock," John patted his shoulder. "You can thank me by getting Mycroft to make the gun charges go away."

"Of course, John."

"Also, you're sweeping up the glass and paying for repairs." John smiled innocently as he waved Lestrade over.

"John." Sherlock pouted.

"You poisoned me." He gave Sherlock a sidelong glance.

"You aren't going to let this go, are you?" Sherlock sighed.

"Not any time soon, no."