They entered a room that had obviously been built by experts. The walls were made with thick, perfectly cut square stones while the floor was tiled with smooth stones, polished and covering every square inch of the room.

Four stone pillars, expertly crafted, braced the roof and each side of the pillar had a bas-relief carved into it. Shining his light on to them, Nate saw the carvings were of a palm tree, a raven and two lions, one on each side.

Below the carvings metal sconces were attached to the pillars, each one containing a torch. Nate grabbed the torch from the nearest sconce and asked Sully to light it. Thankfully the flame caught, and they were bathed in a warm glow, he used the torch to light the fifteen torches and replaced the original one. Most of the room was now bathed in the warm glow of the firelight.

Nate gazed up to the roof to find high, vaulted ceilings, similar to a church that acted as support against the earth above.

"This is a church" Sully said, his voice echoing off the stone walls. "Look, there's an altar up here."

Nate walked to the front of the church and found the Sully examining an altar table, behind him was a stone platform. Climbing on to the platform, Nate walked around it and, where the light failed to fully penetrate, found another stone altar, this one long and rectangular. He studied it in the poor light, running his hand over the smooth surface, brushing away the thick layer dust and found there were lines carved in the stone. He brushed off more of the dust and, turning his torch back on for better light, found a depiction of two lions sitting under a palm tree that ran the length of the altar top. A raven was sitting on one of the fronds of a tree.

Realisation hit Nate like a truck, it's not an altar. It's a coffin!

"Sully, over here!" Nate called out.

His friend approached from the right.

"Check it out" Nate said to him.

"Is that a coffin?"

"I think so," Nate nodded.

"Who is it?" Sully asked.

"Let's find out. Give me a hand."

Nate moved to the head of the coffin, while Sully moved to the base and on the count of three, they pushed. They grunted and groaned, the lid stubbornly remaining in place. They gave it another push and felt the lid give a little.

"One more time" Nate said.

They pushed, "Put your back into it" Nate groaned, straining.

Then the lid popped free and slid off the coffin and a rush of cool, dry air escaped from it, the smell of decay invading their nostrils.

Shining the torch light inside, they saw a skeleton, bones weathered a yellowy brown dressed in decayed rags. The arms were crossed over the chest and a gold cross was clasped in one of the hands. The skull smiled up at them like it was in on a joke. It was in remarkable condition considering the age.

"Who is it?" Sully repeated.

Nate thought about the church, the location and the depiction of the palm trees, the lion and raven and added it up, "This is Saint Paul."

"The Apostle?" he asked incredulously.

Nate looked at him, "What? No, he's in Rome. This is Saint Paul, the Hermit."

"Never heard of him."

Nate frowned, "What happened to being a good catholic boy?"

His friend shrugged, "What can I say? I knew the A-listers."

Nate rolled his eyes, "Anyway, this guy was born in Egypt, around 227, he fled Egypt during the persecution of Christians and lived his life as a hermit in a cave in the mountains of the Theban desert, praying for the world to be a better place-"

Sully snorted.

"-and living off the water of a nearby oasis. Clothed by the fronds of the palm tree and fed by a Raven that brought him a half a loaf of bread every day. He supposedly died in 342."

Sully held up his hands, "Wait a minute, 342? That would make him, what? 120?"

Nate made a face, "115, Sully."

"I rounded up."

"Anyway, this is him."

Sully examined the body, "He's, ahh, relatively treasure-less, Nate."

"Let's just keep looking," Nate said. "See if you can find the sextant symbol around here."

Sully moved off and just as Nate was about to leave, he noticed something on the inner wall of the coffin. Shining his torchlight on it, it looked to Nate like a crudely drawn topographical map. There were two snaking lines, one on top and one on the bottom that Nate thought were two rivers. There was a lake next to the flat grassy area just under the north river and a small outcrop of trees above the lower river. There was also a small mountain or hill south of the lower river. Just above the hill was a picture of a telescope and a picture of an open door with an arrow pointing down next to the lake in the grassy plain. On the top right was the image of Cook's sextant.

Pulling his diary out of his pack, he sketched the map and replaced it. He knew Sully would be eager to see this but decided to show him later, the light was too poor. He stood up and began exploring the rest of the vast church.

It was as Nate was running his hand along a pedestal with a giant wooden cross on it that Sully called him over from the other side.

"What is it?" he asked, arriving to see Sully's torch playing over the wall where four tiles surrounded the image of a man sleeping in a cave. The four tiles showed a picture of a Lion, a Raven, a Tree and the same Raven.

"Have a look," Sully said and pushed on the top left tile, the one depicting the lion. It rotated, showing a new image, this one of a tree.

"World's oldest tic-tac-toe game?" Nate said.

"It's gotta open something, right?"

Nate agreed. There's no way this is by design in such an obscure location. He approached and examined the wall. The man in the middle was delicately carved and was obviously St. Paul the Hermit. He was laying down and apparently asleep. He moved to the four rotatable tiles, he pushed them and they spun around smoothly, each tile had four sides with a combination of: Oasis, Desert, two Lions (each facing in the opposite direction to each other), Raven, Palm Tree, House and Cave carved into them, as delicately as the image of St. Paul.

"We just need to put these in order" he said.

"Well, what's the order?" Sully asked impatiently.

"Just give me a second!" Nate shot back.

While Sully walked off, grumbling and shoving an unlit cigar in his mouth Nate studied the tiles, rotating each one and thinking. They had to have something in common, some sort of reason. A story to tell maybe.

He looked from the image of St. Paul to the four tiles and it hit him. A story, of course!

The Palm tree, the raven and the lions, all representative of St. Paul the Hermit, but so were the building, the desert, the cave and the oasis, all places St. Paul lived, or, as the image was showing, all the places he slept!

The image of St. Paul was the hint for the solution

"Sully, I got it" he called back.

Sully shuffled over and pulled the cigar from his mouth, "What's the answer?"

He began flipping the tiles around, explaining as he went, "It's the story of Saint Paul's journey, from his house-" he flipped the top left tile to the picture of the house, "-to the desert, then the cave all the way to the oasis." He flipped the bottom right tile to the oasis.

The silence was interrupted by a grinding sound and the wall behind the coffin recessed and moved aside like a sliding patio door and a gust of dry air burst out.

Sully clapped him on the back, "You're a genius, kid!" he said laughing. "Let's go."

They approached the new entrance and Nate looked at Sully, "I hope there aren't any mummies waiting in there."

"Mummies? Why would there be mummies?"

Nate shrugged, "It seems like a place a mummy would wait."

Sully sighed and, shining his torch in the entrance, said, "Come on, kid. If I see any mummies, I'll give a shout."

Sully peered into the new area, shone his torch around and then he turned back to Nate, "So far, no mummies."

"That's good," Nate said happily.

Sully walked through and Nate followed. They were in a large, similarly built room with vaulted ceilings and thick stone walls but it was much smaller, and practically bare.

"What kind of room is this?" Sully asked.

"I'm not sure" Nate replied. "I don't see what they would use it-" he broke off as his torch light caught a glint of something on the ground underneath the edging of a pillar. He walked over and knelt down, it was lodged in a crack in the stone floor, easy to miss if you weren't looking for it. He picked it up and brushed off a layer of dust and dirt and examined it in his torchlight. It was a roughly circular gold coin with a thin cross on one side and a front-facing man wearing a crown on the other. The word 'Tib CONSTANTINVS PP AVI' was written around the perimeter of the coin and realisation hit Nate like a bucket of cold water.

"Holy crap!" he almost yelled.

Sully was over in a flash, "What's wrong?"

Nate showed him the gold coin, "It's a Solidus."

"A what now?"

Nate handed him the coin, "It's a gold coin - currency - from the Byzantine era. The picture is of Tiberius II Constantine, Emperor of the Eastern Roman Empire around 575."

Sully rubbed the coin with his fingers, "What's a Byzantine gold coin doing here in the church of a Saint?"

"I have no idea."

"Well at least we have some treasure."

Nate considered, "Keep looking, maybe there is more of it around here."

They searched the floors and pillars and Nate was about to give up when Sully called, "Nate I think I found more of those coins."

Nate walked over to Sully who was shining his torchlight on a pair of coins he found.

"Let me see," Nate said, taking one of the coins from Sully and looking at it in the light of Sully's torch.

"It's definitely not a Solidus" Nate said examining it. This coin was silver, almost a perfect circle with a notch on one side and another perfectly adjacent to it. One side bore the image of a double-headed trident, he flipped it over to see a strange geometric design that looked like squares overlapping each other, kind of like a Venn diagram but with many more sets.

"I'm not sure what it is," he said. "I've never seen anything like it before and I don't know who's symbol that is meant to be."

Sully shrugged pocketing his coin, "Worry about it later. Let's keep looking."

They continued their exploring, Nate to one side and Sully to the other.

"It was about five minutes before Nate heard his name being called out again.

"What's up..." Nate trialled off as he arrived to where his friend was waiting. His light was shining on a pile of stones, different to the ones that made up the walls of the room and followed it up to an opening in the wall, about chest height.

Peering inside, he saw it was a small room, the size of a ship's crew cabin. There was a desk on the left and a small cot against the back wall. Kneeling with elbows perched on the cot base was the skeleton, hands clasped together in an eternal prayer. Hanging from his hands was a wooden cross on a gold chain.

"Who the hell is this now?" Sully asked.

The skeleton was dressed in a brown robe, surprisingly well preserved, but aside from that there was no way to discern him from any other member of the church. Even so, Nate already knew who he was, "This is our good thief, Dominik Martinus."

"Was he walled up in here to die?"

Nate examined the area around the hole in the stones, he noticed there were marks on them, like scratches and dark marks around them. Blood stains.

He nodded to Sully and indicated the markings on the stones, "Seems so."

Sully blanched, "Horrible way to go."

Nate agreed. He moved to the desk where he found a brass candle holder, a dried-up inkwell with quill next to it and a leather-bound book.

Carefully, he opened the book to the first page, it read, in shaking handwriting: The Confession of Dominik Martinus.

"Christ, these guys love to write out their confessions, don't they?" Sully said, over his shoulder.

Nate nodded, "Who knew being walled up to die would give you some perspective."

Turning to the next page, they read.