It all started with one red-colored M&M, carelessly left by their latest suspect near the body of the victim.

Sherlock spotted it lying in the mud, and tweezered it up into an evidence bag, considerable glee written on his face.

"The suspect is a short man with glasses who has a white bulldog. Drives a foreign car," said Sherlock, holding the muddy M&M in the bag up to the sunlight to examine it better.

Even Lestrade, who had seen this before, couldn't believe Sherlock had pulled all of THAT from an M&M and two minutes at the crime scene.

"How?" he said faintly.

Sherlock sighed.

"Car fibre- here, attached. Too coarse for anything but an import. Attached to that is the short hair of an English bulldog. The way the victim's lying suggests the suspect's glasses were knocked off in the course of a fight, in the mud, here," said Sherlock, pausing at a dent in the mud by the corpse's leg and pointing."He couldn't see what he was doing-a victim shot in the neck? He was aiming for the head. And his length of stride proves he's short. Much like John here..."

"Hey!" said John.

Sherlock's eyes narrowed.

"I MEANT he was your height, give or take an inch or two."

John huffed, not completely mollified.

While Lestrade and company searched for the suspect, Sherlock decided to study the man's M&M preferences.

John didn't bother to ask why-it wasn't worth the half-hour of breath Sherlock would waste trying to make it make sense to him.

It started with a few packages of the peanut and plain, and it quickly descended into multicolored, 'won't melt in your hand' madness.

John arrived home on Day 3 of the case to find 221B's sitting room converted to an M&M wonderland, with jars of colored candy on every flat surface (and some not so flat.)

Sherlock was in the middle of it all, separating a small heap of the candy into colors.

"How? What?" said John, moving a jar marked 'CRUNCHY ORANGE' out of his chair.

"Solved a break-in at a local sweet shop. The owner graciously offered to help me out."

John shook his head in disbelief.

"So one case might solve another."

Sherlock grinned. "Precisely."

John nodded and went to put the kettle on, but then had a sudden thought. He walked back around the corner.

"What are you going to do with all of these once you're finished with the case?"

Sherlock looked down at his multicolored hoard with a speculative eye.

"Don't know."

The suspect was caught with the brilliance of Sherlock's M&M analysis, and so the consulting detective strode into Scotland Yard with an air so full of smug Anderson had to leave the area for fear of contamination.

The next day, John returned to the flat to find the jars of M&M's missing from the front room. He would have pondered this, had he not heard moaning coming from the direction of the bathroom. He came around the corner of the room and stopped at the door.

There lay the world's only consulting detective, in the middle of the floor, his face ashen as he clutched at his stomach.

John didn't have to deduce this one.

"How many did you eat?"

Sherlock gazed at him with pained eyes and said faintly, "I lost count at...was it a thousand?"

John shook his head. He'd seen kids eat candy till they hurled, but a supposedly adult sociopathic genius? That was a new one.

John applied his considerable medical skills, and Sherlock recovered quite nicely by the next morning.

However, after eating over a pound of M&M's, he never wanted to see the things again. John saw this as a plus...and apparently so did Anderson.

Somehow, it got around that the most brilliant resident of 221B had gotten sick on the candy. John's blog might have been to blame.

And so Anderson saw it as his mission in life to eat a bag of M&M's at every crime scene, in full view of Sherlock.

Sherlock would turn a little bit green, glare at Anderson, then cleverly deduce who he was shagging around the precinct this week.

And John would pull them apart when it appeared punches were imminent.

This went on for some time, until the day that someone MAY, MAY have dripped a little bit of something into Anderson's candy when the stupid man left the bag sitting on the edge of a car's windscreen.

Anderson heaved all over the victim, igniting Lestrade's temper and nearly getting himself fired in the process.

Sherlock watched the whole scenario with a barely suppressed smile.

Anderson suddenly and abruptly lost his taste for M&M's, though no one but a certain consulting detective (maybe) could ascertain what the cause was.

In someone's hard drive of a mind, justice was served.