A/N: This is the result of an excellent one-word prompt I got from Teej: "Tunguska".

I'm not an idiot!

John arrived home after a stressful shift at the clinic. It was cold and flu season, and if that wasn't enough, he'd been bitten by a two-year-old who had been brought in by his harried-looking mother for what turned out to be an ear infection. Apparently little Joseph was of the firm belief that teeth would get the point across in a much more succinct manner that a simple "ouch, that hurt!"

All John wanted was a cup of tea and maybe a biscuit or two. What he most emphatically did not want was Sherlock and Mycroft in the midst of an argument in the middle of the sitting room.

"Sherlock, your presence has been requested by the highest in the land. You cannot say no!"

"I think you'll find that I can. No, brother mine. No, I will not be pulled into handling another affair of state. No, I don't care if it was the King himself who asked for me. No!" said the curly-haired detective as he paced about the room, dressing gown flaring around him like a cape.

John stood in the doorway to the flat and, seeing the looks on the two men's faces and deciding he wanted no part in whatever was going on between them, he announced to the room, "Afternoon Mycroft, Sherlock. If you'll excuse me, I've had a hell of a day and I'm for a shower." A quick nod to Mycroft and John hurried up the second set of stairs to his room, grabbed his robe and towel and quickly scurried back down the stairs, past the sitting room and into the bathroom where he closed the door with a deep sigh of relief.

Twenty minutes later, John emerged, refreshed and revived and ready to face anything his roommate could throw at him. As he wandered into the sitting room towelling his hair dry, he heard the sarcastic tones of the British Government say, "… if we're not careful in the handling of this matter, Sherlock, we could have another tongue gusher on our hands."

"What are you talking about?" exclaimed John, who then metaphorically kicked himself for having spoken. He was pretty sure he had misheard, but knowing the Holmes brothers as he did, wasn't willing to dismiss 'tongue gusher' out of hand.

An annoyed sigh came from the lanky detective now standing in front of the window. "Tunguska is a remote area in Siberia where, in 1908, an asteroid exploded between 9-16 kilometres above the earth. The resulting shockwave resulted in the devastation of approximately 80 million trees. Its effects were measured as far away from the site of the blast as England. Any idiot should know this, John," added Sherlock in an aggrieved tone.

"I'm not an idiot, Sherlock," snapped John as he draped his towel around his neck. "I'm fully aware of the Tunguska Event. I simply misheard Mycroft as my head was covered by my towel, you git. I heard 'tongue gusher' instead of 'Tunguska', that's all."

"Tongue gusher?" said Sherlock in disbelief. "Why in heaven's name would Mycroft say 'tongue gusher'."

"I don't know," answered John with a fond smile aimed at his friend, "but having been exposed to you two for as long as I have, I wouldn't put it past either of you to be planning some obscure sting operation code-named "Tongue Gusher". Tea anyone?"