John didn't believe in ghosts, so when the case took them to underground Edinburgh, he thought little of it. He thought instead of the map of the caverns that Sherlock had acquired. (John didn't ask where.) He thought of their current liaison to the Edinburgh Police, and Lestrade's old friend, D.I. Sophie Marquardson. (John didn't ask how friendly.) He thought about the vast crowds of Fringe Festival attendees who by their sheer volume were inadvertently impeding their search. (Bloody tourists.) He thought about how nice it was to be in Edinburgh when the weather was, for once, warm. (He'd not brought a single wool jumper in his hastily packed over-night case.) But mostly he thought about the investigation.
The police had evidence suggesting the murderer was hiding out down in the catacombs somewhere. It seemed a fitting spot, in John's opinion. He and Sherlock had taken one of the ghost tours last night, posing as festival goers on holiday. In fact, it had been reconnaissance. John hadn't expected anything unusual to occur then, and he'd been right. Even passing "the most haunted part" of the catacombs, nothing untoward or unearthly had happened.
So why did he feel uneasy now?
John shivered. The warmth of the day had not made its way below ground, and hours had passed since the last ghost tour of the night had gone. He knew the stones around him were a dull grey patched with black and brown, but the small section illuminated by his torch glowed bluely through the tinted lens. The blue lights would allow him and Sherlock to see reasonably well without revealing their location to their quarry as easily as ordinary white light would.
A soft glow ahead made him pause. He knew it wasn't Sherlock; the light had a yellowish hue. John pressed his back to the cold, rough stone and peeked cautiously around the archway.
No one. A candle stood where he'd not seen one last night, in an iron ring holder in a cubby that the guide had explained would have served as someone's bed. It was distinct from the surrounding cubbies, with a stylised flower carved and blackened into its edge. He looked around, trying to take in every detail, trying to think analytically about what he saw. But what he saw was no sign of anyone or anything else. The feet of passing tourists had scuffed the ground, and he saw no new prints overlaying theirs in the thin dusting of dirt and fine gravel.
Every sense on alert, he skirted the area and continued on.
A breath of chilled air ruffled the hairs at the back of his neck and he turned swiftly.
Nothing but blue-lit darkness and stone.
A scuffling sound reached his ears, but with the strange acoustics he couldn't tell what direction it came from. Sherlock and he had split up early on, their plan to either corner the culprit down here or drive him up to where D.I. Marquardson's team waited at either entrance. John took a best guess and hurried toward the sound.
He hit a wall of chilled air as he passed a gated corner, but he didn't slow down. He smelled the sour stink of stale breath and cheap whiskey. Then something hard struck him dead centre of his chest, knocking the air out of him, and he fell. His head hit the cold, hard ground, and everything went black.
He came to with Sherlock's pale and worried face hovering inches from his own. The catacombs were lit properly now by the electric lights the city and the tour company had put in. It hadn't seemed so bright last night, though. He squinted painfully up at his friend.
"Did you get them?"
"There was only one, and yes."
Sherlock helped John sit up, and John felt cautiously at the back of his head. His fingers found a painful lump, but they came away unbloodied. He suspected that a check of his pupils would detect mild concussion. Not that Sherlock would think to check. He took the icepack Sherlock offered, too pained to wonder where he'd gotten it, and applied it to the back of his head.
"Can you tell me what your attacker looked like?"
"There no evidence that the murderer had an accomplice. It's likely whoever it was was simply some ordinary thug or a street person taking shelter here. You must have caught him off guard and he panicked. Surely you have an idea what he looked like. Basic size and shape, at the very least. Even in the limited light provided by your torch, you must have seen him coming at you."
"There was no one there to see. I heard noises that I thought must be you struggling with the murderer."
In other circumstances, John might have taken a bit of pride at Sherlock's implied commendation. "I ran towards where I thought you were and then--" He'd have shaken his head if it didn't hurt so abominably. "There was a cold patch of air, then something hit me in the chest, and I went down." Absently, he rubbed at his sternum with his free hand. "Ow!"
"What is it?"
"Probably a bruise from whatever hit me. Felt like a bloody two-by-four."
"Let me see." Before John could protest--not that he planned to--Sherlock's long fingers quickly unbuttoned his shirt.
John couldn't hold back a shocked gasp, and even Sherlock looked uncharacteristically surprised.
Where he'd expected a blossoming bruise was instead a perfectly formed, harshly red handprint. Sherlock held up his own hand and placed it over the impression. "Male, approximately five feet and eleven inches tall, roughly seventy-nine kilos, approaching at--"
"God, Sherlock, shut up."
"You two all right?" D.I. Marquardson's voice was a welcome interruption as far as John was concerned. He didn't want to think about who, or rather what, had taken him down so forcefully. The last thing he needed was Sherlock analysing it all and trying to make it make logical sense.
"Just about." John climbed to his feet with Sherlock's assistance, icepack still pressed to his aching head.
"I'll have one of my team drive you to hospital, so you can get that looked at."
"Good idea." John adjusted the icepack and rubbed again at the aching spot on his chest. He glanced down and had to stop a moment in confusion. The handprint that had been there moments ago, scarlet and clearly defined, was now only a slowly purpling bruise of indeterminate shape.
He looked at Sherlock, who returned the gaze with an inscrutable expression.
"When you have eliminated the impossible " Sherlock began in a voice pitched to carry no further than John's ears.
John shivered. "Let's get out of here."
They followed Marquardson through the maze of caverns. Passing a familiar spot, John had to look twice. There was no time to stop and ponder what had become of the candle in the iron ring, only a moment in passing to note that it was gone. And then they were at the stairway. They climbed the narrow steps, Marquardson first, followed by John, and then Sherlock behind him with a steadying hand on his friend's back.
They emerged into the predawn light of Edinburgh in August. John gratefully inhaled the fresh air and allowed Sherlock to lead him to the waiting squad car.
John didn't used to believe in ghosts.