"Ok," winched Fred in the darkness, "that really hurt."

"I dunno," replied George using the wall to help himself up, "it wasn't so bad."

"That's probably because you landed on me."

"Sometimes you can be so picky. We did fall quite far, but you have got to admit sliding down that tunnel was fun," said George fumbling for his wand in his pocket, "Lumos."

The two brothers shielded their eyes as the wand illuminated them. They were standing; or at least George was, in a small cramped passageway. Looking back they could see that the tunnel they had slid down had closed over. George bent down and picked up the compass that he had dropped.

"It won't budge," he grunted reaching up to try to force the chute open once again.

Fred pushed himself to his feet and brushed the dirt off his knees. He looked across at his brother who had given up trying to pry the opening free and they both glanced down the dark passageway. "Guess that's the only way."

"I wonder where it leads?" echoed George's voice ahead of the light as the twins slowly made their way along the tunnel, "the map doesn't show this place either."

"It's a lot like the one into Hogsmeade," commented Fred as his brother wiped the Marauder's Map clear, "maybe it'll take us there?"

"Maybe," replied George stooping under a low part of the ceiling, "but I have no idea what direction we are going in."

"What about the compass?"

"What about it? It doesn't tell us where North is."

"I know that but are we heading in the right direction."

"It depends on what you mean. Do you mean the way out or towards a rather nice toffee apple? Cos either of those would be the right direction."

"Actually I meant are we heading towards the treasure? God, I haven't had a toffee apple in ages."

"Er… you had one today, remember after lunch?" reminded George flicking open the box and looking at the arrows, "yep, it's pointing straight ahead."

The twins steadily made their way down the dark passageway, their wands only managing to illuminate a short distance ahead of them; not that either of them really noticed as they had dissolved into arguing over whether or not a chocolate apple was superior to the toffee variety.

"Look I'm just saying that toffee apples came first, therefore they are better," said George from the front of the two-man procession.

"Well by that logic I am better then you."

"How do you work that out?"

"I was born first," Fred pointed out, causing George to stop in his tracks.

"Er…no, I was born first," corrected George.

"Since when?" frowned Fred his hands on his hips.

"Since about ten minutes before you were."

"And mum says you were first, does she?"

"Oh I never asked mum. I just assumed I was first, what with being the good-looking twin and everything."

"I'm sorry," repliedFred shaking his head, "I must be getting sleepy, because for a moment there I though I heard you say that you were the good looking one."

"Not just the good-looking one but the clever one too."

"Ok now you are just being silly, we both got the same mark on that Herbology test last week."

"You copied off me," said George waving his finger accusingly.

"Yeah and you copied off Lee."

"Hmm good point," nodded George, "ok fair enough we are just as smart…"

"…and?"

"…and nothing. I still maintain I'm the good-looking one. How about when they get back we just ask the girls which one of us is better looking?"

"Suits me fine," replied Fred before pushing past his brother, " and now if you don't mind let's find that treasure."

"I'm also taller then you."

The bickering continued as the brothers slowly made their way down the dark passageway and didn't stop until it eventually led into a large cavernous room. As the brothers stepped through the tunnel and into the room they gave it an appraising look, which didn't really take long as they was nothing in the catacomb save for a concrete plinth in the middle.

"They could do with some decorations in here," commented Fred looking around the room, "or at least a window."

"YeahI expected something a bit well grander to be honest."

The twins approached the plinth in the centre of the room,and as they drew closer to it they realised that there was something placed on top of it.

"It's the fourth piece," shouted Fred excitedly punching his brother on the arm and rushing forward.

"Wait!" ordered George just as Fred was about to pick up the stone slab.

"What?"

"Doesn't this seem a little bit familiar to you?"

"Oh, well now you mention it…" Fred paused and scratched his head.

"It's like when we found this," said George giving the compass a little wave.

"Yeah that's it," nodded Fred before casting a sideways look at his brother, "is that important?"

"Do you remember what happened when we picked this up?"

"Oh yeah, that nasty blade," Fred looked down at the plinth and step a few paces back, "any ideas on how we should get it?"

"Erm…we could try to knock if off with something."

"With what?" replied Fred waving his arm to indicate the otherwise empty room.

"I don't know," shrugged George looking around on the floor for a rock to throw, "I suppose we could just chuck one of our shoes at it."

"Yep we could do that," nodded Fred in agreement, "or we could remember that we have wands and just levitate it."

"Oh yeah," grinned George, slipping his right foot back into his shoe.

"Windgardium Leviosa," Fred gave his wand a quick swish and flicked it in the direction of the plinth.

A few moments of uncertainty passed before the stone slab began to rise and wobble shakily in the air. George let out a whoop of excitement as his brother slowly drew the stone towards them and grasped it triumphantly in his hand.

"Wicked," smiled George holding out the compass so his twin could slot the final piece into the side.

Fred gave his brother a quick excited look as he clicked the stone into place. They both waited with bated breath, watching the box on the palm of George's hand.

Suddenly one of the arrows sprang into life and began spinning wildly around.

"This is it brother," exclaimed Fred beaming from ear to ear.

The second arrow also began to twirl quickly around.

"We are going to be so rich," laughed George, never taking his eyes off the box.

Without warning the box abruptly snapped itself shut, the crack echoed loudly around the room. The twins waited expectantly. And waited. And waited.

"Er…shouldn't it be showing us where the treasure is?" asked George still holding the box out on his hand.

"Give it a minute."

"We've given it about five already."

"Maybe we had to do something else to it," said Fred. He took the box out of his brother's hand and tried to open it again, "damn, now it is stuck again."

"Hey there is something on the bottom," George pointed at the box, which his brother had begun to shake left and right in an attempt to get it to open back up.

Fred flipped it over and they both looked at the bottom of the box. Instead of the usual smooth wooden finish there were words scrawled across the back of it in red writing that seemed to glow under the wand light.

"What's it say?" asked George trying to read the words upside-down.

"Litha"

"Well what on earth does that mean?"

"I think it means that this thing won't work until we find out what Litha means," concluded Fred, "it could a person or a place or a treasure."

"Well that's just perfect isn't it," complained George shaking his head, "talk about a waste of time."

"It wasn't a waste of time," corrected Fred waving the box under his brother's nose before sticking it in his pocket, "we just need to work out what this Litha is and then we'll be laughing."

"Prevend was here nearly two hundred years ago, do you honestly think this Litha is still around?"

"You always look on the bright side don't you? Come on, let's go home."

"And that's another thing," George carried on venting, "we only got past Schim in the first place cos we were hidden inside a cabinet, how are we suppose to get past him on the way out?"

"Originally I planned an exciting escape involving us using smoke bombs and heavy disguises."

"And now?"

"I think we'll wait for the door to slide open and then we just leg it."

"Smooth," replied George giving his appraisal of the plan, "fine let's go and see if we can figure out how to get back into the Slytherin Common Room."

The brother's turned away from the plinth and back towards the tunnel. They both froze in their tracks and looked wildly around. The way out had disappeared; in its place was solid rock and dirt just like the rest of the catacomb.

"Where's it gone?"

"It has to be here," shouted George frustratedly pushing his hand against where the passageway used to be as though he was attempting to force it back open through the dirt, "a tunnel that big doesn't just suddenly disappear."

"Hey check this out," called Fred, who had been wandering around the cave to try and find another way out. He was standing next to the plinth looking down at it, "there is more writing."

"What does it say?" asked George striding over, "'start digging' perhaps?"

"It says 'Solvo Sidon'," replied Fred examining the writing.

"Well that sounds like a load of help," George shook his head as he gazed down at the plinth. He looked back at where the opening of the tunnel should have been, "I bet when we took the stone off this thing, it triggered a trap that closed the way out."

"Great, so not only are we trapped down here, it turns out it's our own fault," said Fred still looking distractedly at the writing, he traced his finger along a groove etched into the stone that ran underneath the words.

Fred paused for a moment looking at the words. There was something strange about them but he just couldn't quite put his finger on it, even though he was in fact currently putting his finger on it. He leaned close to the plinth and his eyes flicking across the stone as though expecting the words to gradually make sense.

He suddenly frowned and moved his head back away from the writing, waited a few seconds and then lent forward once again. George, who had been examining the rest of the catacomb for a possible way out, stared over at his brother with a look of bemusement on his face.

"Hey check this out," called Fred as he continued to bob his head back and forth making it look as though he was impersonating a chicken.

"Well done brother," replied George kindly, "it looks like you have got it down to a 't'."

"What?" frowned Fred pausing, "no, not that you idiot. I mean look at this. When I move close to the words, the letters seem to glow."

"Really?" asked George continuing to check along the wall, "so instead of words we don't know the meaning to, we now have glowing words we don't know the meaning to."

While George carried on testing the walls for any clues to a possible exit, Fred persistent with bobbing his head up and down making the letters glow and dim repeatedly. He tried to work out just what the glowing letters meant, as he was sure they had to have some other purpose.

He placed his hands on the cool stone and closed his eyes as he attempted to make sense of the situation, but unfortunately no sudden inspiration flooded over him. He sighed in frustration, opened his eyes and gazed back down at the letters.

His eyes opened wide as he saw that the letters were glowing brightly without his face being close to it. Fred looked down at his hands and slowly moved his left hand away; the words remained illuminated, he then moved his right hand, which still contained his wand, away and the letters fell dark once again.

He continued to experiment with the glowing letters, waving his hand back and forth over the stone causing the letters to flash with varying degrees of brightness.

"Oh," sighed Fred as realisation gradually dawned on him, "it's not me making it glow, it's the wand."

He pointed the wand down at the stone; its point just inches from the words. The letters grew exceedingly bright but even more intense was the groove underneath them. It was practically pulsing with light. Fred moved the tip of his wand over the furrow and traced along its length, matching the curves and arches along the way.

The letters glowered at him bright then before. So he traced the groove again and again, and each time he did, it seemed to make the light more and more concentrated.

"Solvo Sidon," Fred mumbled, reading the words out-loud as he traced his wand along the groove once again.

The stone plinth suddenly burned brightly as the entire thing lit up, causing Fred to shield his eyes against it. As soon as the light appeared it abruptly stopped.

"What did you do?" asked George urgently, running over to his twin.

"Nothing," shrugged Fred attempting to sound innocent. He caught his brother's look, "well ok, I just sort of read out the words whilst I waved my wand."

"Oh, so basically you cast a spell?"

"I guess so," admitted Fred.

"A strange spell, and we don't know what it'll do."

"What's the worst that could happen?"

"Now, why did you have to go and say something like that?" scolded George, "we are trapped, underground, and no one knows we are here. Do you honestly want to know what's the worst that could happen?"

"I dunno, maybe Percy will turn up and want to read us his essay on Goblin mining in the twentieth century again," ventured Fred causing both the twins to shudder at the thought.

"Hang on, can you hear that?"

"Yeah, it sounded like you saying 'hang on, can you hear that?' " grinned Fred. His brother just gave him a look, "actually now that you glare at me like that I think I can hear something. Like a rumbling sound."

"It sounds like it is coming from over there," said George pointing to the far end of the cave.

The strange noise continued to get louder until there was a muted thud against the wall. The rumbling sound had disappeared and was replaced by a low creaking noise.

Fred looked across at his brother who just gave him a brief shrug of confusion. The creaking sound began to get more intense. The twins backed away from the far wall as much as they could, not knowing what to expect.

Suddenly a small mass of dirt shot across the room hitting the wall next to them. They looked at the clump on the ground, then up at the wall that it had hit, and then at the far wall. The brother's hearts sank. Where the dirt had been, was now a hole, and through that hole a constant stream of water was pouring through.

"What do we do now?" shouted George panicking.

"Let's block it back up," replied Fred grabbing the Quaffle sized ball of dirt and running to the far end.

The water was cold against their ankles as they waded uncertainly through the loud rushing water. It took both of the boys together to force the piece of dirt back into place. The torrent of water slowed but it still trickled down the sides of the opening.

"Now what?" asked George his soaked hair matted to his head, "we can't stand here forever."

"I dunno, let me think."

"Great, I guess that is one way to make this situation worse."

Before Fred could come up with a snappy response a new stream of water appeared in the wall as another bullet of dirt was fired across the room.

"It's no use," panicked Fred, as a third hole appeared, "there are too many."

"We'll have to try and open up the tunnel again," shouted George over the rushing water.

"Right."

They let the hole they were trying to block spring back into life and push their way through the now ankle deep water. Standing next to the plinth the twins tried in vain to work out how it had caused the tunnel to close.

They prodded it, poked it with their wands, shouted at it and finally kicked it, but nothing seemed to make the slightest bit of difference. The water level just kept rising, and the tunnel remained stubbornly shut.

When the water had reached about waist height the bottom half of the far wall suddenly gave way under the pressure. The twins were swept away from the plinth and slammed into the side of the catacomb by a wave of water, stone and dirt.

"Fred you ok?" shouted George spitting out a large mouthful of water.

"I'm fine," replied Fred spluttering as kicked his legs to keep him afloat, "well at least it doesn't seem to be filling up as quickly."

"Yeah, given the choice I would always prefer to drown slowly rather then quickly."

"Hey look at this," cried Fred holding up what looked liked a green cloth.

"Very pretty, but I'm not sure if it is your colour."

"No you idiot… hey I always thought I looked good in green, anyway look its one of those plants we learnt about in Herbology. Remember?"

"Nope, can't say I do."

"You and Lee ended up wrapping them around your heads."

"Oh the hat plants," nodded George swimming over to his brother, "and how does that help us?"

"Because, you idiot, these…" Fred waved the large leaf around splashing water as he did, "are only found in deep fresh water."

"Right."

"Like the lake."

"Oh," gasped George, "you mean this water is coming in from the lake."

"Yep, which means we just have to swim out and we'll be free."

"What if we can't hold our breaths long enough?" asked George deeply concerned.

"Well seeing as the water is still slowly rising either way we are going to have to hold our breaths at some point."

With the twins decided on a plan of action they kicked away from the wall and swam towards the far end of the cave where the wall had collapsed. George gave his brother a silent nod that he was ready, they both took a final lungful of air, transferred their still lit wands from their hands and clamped them into their mouths and dived.

George followed his brother through the submerged opening and they began to kick their way along the eerie looking tunnel. The cold water flowed around their bodies, making them have to swim harder then usual against the slight current.

Gritting his teeth down on the wood of the wand, George grimaced as he tried to shut out his body's urge to shiver against the cold. Suddenly his hand became enveloped in something slimy. Panic surged through his body as he jerked his hand away.

George nearly forgot he was underwater and almost laughed with relief as he realised that he hand had become entangled in a particularly large leaf from an underwater plant. He wriggled his fingers free and pushed the green offender away.

His arms and legs began to ache as he forced himself through water. He could see his brother further along the tunnel swimming out and up into the lake itself. George's lungs began to burn as he gratefully kicked away from the lakebed and up towards the surface.

Kicking as hard as he could George pushed himself away from the bottom of the lake. Above him he could see the faint glimmering light of Fred's illuminating through the gloomy waters. George tried to move his tired legs harder through the water but the lack of sleep, and the wet heavy clothing made it difficult to make much progress.

George's chest felt as if it was about to explode, as he frantically tried to scramble through the water to the fresh air. Bubbles erupted around his face, as a fish darting out of the dark and towards his face spooking him, and causing him to violently exhale the remaining air in his lungs. George grimaced and bore down on the wand between his teeth while he desperately struggled to reach the surface.

He was too tired. The distance to the surface too great. George slowly began to sink back towards the depths of the lake, his vision gradually blurring and fading. Suddenly he felt something wrap itself around his arm and drag him upwards.

He broke the water spluttering and gasping for air as he hurriedly took in much needed oxygen.

"Th…anks….Fred," he managed to say between wheezes.

"Don't thank me," called Fred's voice from a little way off, "thank him."

George looked over at his brother, who was grinning wildly and nodding behind him. He slowly turned his head and looked across at his arm. There was a long thick black tentacle enclosed around his wrist. George's gaze slowly trailed up the length of the slimy arm until he saw the bulk of the Giant Squid silhouetted against the moon.

"Er…cheers," thanked George, still panting slightly.

"He grabbed me then went back to save you," explained Fred swimming over to his brother. Scooping George's dropped wand out of the water he passed it back.

"Thanks," replied George still looking at the Giant Squid a bit awe struck. He shook his head clear and turned to look at the edge of the lake, "I don't think I'll have the energy to swim back."

"No problem brother," grinned Fred, patting the Squid's tentacle, "I had an idea about that."

"You know they never put this in the letter we got last summer," said George a few moments later from atop the back of the creature

"I know," agreed Fred shivering slightly in the cold, "they should have put 'you get to ride on the back of a Giant Squid' rather then all that nonsense about books and equipment."

"Hey," called George squinting into the distance, "are there people on the shore over there?"

"Yeah," agreed Fred warily after a few moments, "I think there are four of them. Just try and act normal."

"Normal?" asked George looking behind him as the squid gave another swoosh with its tentacles sending it gliding along through the water, "I guess anything is worth a try."

As the trio of the twins and the Giant Squid got closer and closer to the bank of the lake, two of the figures on the shore broke away and moved across to meet them. The brothers steeled themselves for the assumed following onslaught of interrogation, however their fears were cast aside once they realised that the two people on the shore were familiar faces.

"Alright Miro," Fred waved as he climbed off the Giant Squid's back, down one of its tentacles and onto the shore.

"Hiya Bruv," added George.

"You are aware that you aren't allowed out of the Tower after dark? Let alone to go riding on the back of the Giant Squid," warned Charlie

"Charlie?" asked Fred slyly as the four boys bade goodbye to the squid, "What are you doing out of the school after dark?"

"Er…"

"Alright," George gave a cheery wave to Miro and Charlie's two companions, which turned out to be one of the girls on the Quidditch team and another Gryffindor girl who he recognised but couldn't name.

There was a moment of silence in the air; the only sound was the occasional hoot from a passing owl and the splashing from the Giant Squid heading back out into deeper waters. Each of the four boys weighed up their next course of action warily.

"O.k." said Charlie slowly, "we didn't see you if you didn't see us."

"Didn't see who?" asked George.

"Exactly."

"No seriously, didn't see who?" asked George again, "I wasn't listening."