Rodney stalked between the walls, his fists clenched and his mind whirling with anger. He was SO done with this maze. Energy. Amplitude. Time. These were beautiful, universal concepts and this torture chamber disguised as a puzzle was twisting them, distorting nature itself. To use the very concept of sound as a weapon was… blasphemy.

He rounded another corner and saw only another turn ahead of him. Frustrated, he threw a fist against the wall as he turned. It vibrated with a long, low bonggggggg. So low, it was almost inaudible. He jerked the hand back, afraid he'd triggered the puzzle's sound torture again, but the vibration faded.

No less angry, but a little more cautious, he continued through the maze, going over everything they'd learned or seen while in it. The last puzzle wasn't even a riddle with an answer. It was just a clue. Maybe that's how they should think of the puzzle stages - as clues rather than questions to be answered. But what the hell did any of it have to do with getting out?

"Teyla. Help me with him."

Ronon's voice drifted from beyond the last turn and Rodney jogged back to his teammates, not having realized he'd gotten so far ahead. When he saw Teyla and Ronon juggling a limp and nearly unconscious Sheppard, the anger returned, only slightly less potent than his fear for his friend.

"He cannot walk any further," Teyla was saying.

Rodney agreed with her. John was so pale, he looked almost translucent. He was breathing hard in great raspy gasps and sweat slicked his brows and neck. If he was conscious, it was in name only - his eyes were glazed and he seemed unaware.

"I'll carry him. Help me get him over my shoulders."

Together, Rodney and Teyla helped Ronon tug John into a fireman's carry where he went limp, almost with relief.

"Let's just hope we can wake him up at the next puzzle stage," Rodney growled.

They walked the final turns to the next courtyard in a close clump. Rodney at Ronon's elbow to help support the incredible burden the man carried, Teyla close beside John's head crooning desperate encouragement.

When they struggled the last steps into the final courtyard, they all paused, taking it in. Rodney knew it must be the final puzzle, because this courtyard had the look and feel of an open-air concert - minus the band or any crowds. This stage was against the far wall instead of centered, and was lit with colored lights. Rodney couldn't see any source of the lights, but he'd given up trying to make sense of this place.

As they slowly made their way across the empty space towards the stage, Rodney realized that this time, the stage was also made of the same material as the walls. As they got closer, he saw that, in fact, the stage WAS part of the wall - a seamless extension of creamy Kong rubber (to borrow Sheppard's description even though Rodney would argue til he passed out that the material was anything but natural rubber) molded into the shape of a platform and podium.

They didn't speak. Each was holding their own fear in check. They simply climbed the two short steps to the platform and helped Ronon slip John off his shoulders where he slid down the wall into a heap. Rodney crouched with Teyla as she began to pat his cheek, trying to rouse him. When gentle didn't work, Ronon pulled and sat him upright against the wall, then gave his shoulder a shake. Rodney thumped John's sweat-spiky hair.

"Sheppard, I know it's probably a lot more comfortable where you are than here, but we need you here. This has got to be the last puzzle and that's either great or really terrifying."

Teyla jerked her head towards Rodney. "You think this is the last puzzle?"

"I don't know of course, but the stage is different. The lighting is different. It feels like a performance or something. The big finale."

John was moaning and Ronon shook his shoulder harder. John's head bobbed off his chest, then with a great groan, he writhed against the wall, his face a mask of pain, his body tense and shaking. His eyes flew open and he looked wildly around. Another gasp, then groan, escaped through tightly clenched teeth.

"John!" Teyla cried, her voice broken with sympathy. She knelt beside him to press him firmly against the wall and keep him from sliding sideways.

"Huurrrrts," John gapsed. "Can't breathe." He writhed again, one hand clawing feebly at the wall, the other clutching at his shirt as if loosening it would help him breathe.

"Solve the puzzle, Rodney!" Teyla commanded. "Do it quickly. GO!"

Rodney scrambled to his feet and was grateful when Ronon followed him, weapons drawn. He didn't even pause as he stepped up to the podium. He was no longer worried about the riddles. They were simply the means to the true end which was to pass the test that followed.

The stone tablet was there with only four words written on it.

"Solid, Liquid, Gas, Plasma," he read aloud carefully, then looked around with a jerk for the snake or the energy field or whatever horror was to be unleashed. Nothing happened. The courtyard was silent except for Sheppard's increasingly frantic groans.

"What's it mean?" Ronon grunted, also looking around, his arms bulging as he readied his weapons.

"They're four phases of matter. Ice is the solid phase of water, for example."

"What's it mean?" Ronon repeated.

"I don't know, yet. In the last three puzzles, the answer had something to do with the correct response to the attack. Do you see anything?"

"No."

Still, they waited. Still, nothing happened.

"The wall closed," Ronon said. Rodney jerked his gaze to the section of the wall they'd passed through only minutes ago. A quick scan confirmed that no new door had opened.

"We're stuck here? Where's the test? The attack? Why the hell go through all that only to sit and rot at the end?"

"Ronon! Help me!"

Teyla's cry jolted their attention back to John who was in the throes of a convulsion. Teyla was struggling to keep him pinned against the wall as he twitched and writhed. Ronon flung himself down on John's other side and together they held his shoulders against the wall until the seizure slowed. John finally stopped twitching and sat in a limp sprawl, his head slowing banging against the wall creating a constant low bonggggg that set the whole courtyard humming.

"His pulse is racing. His respiration is shallow and labored. His skin is cool and clammy. Rodney, John is dying. The venom is overwhelming his body. We must get him to help. What was the last puzzle? How do we at least move on?"

Teyla's icy calm matter-of-factness was more frightening to Rodney than any display of panic. He just stared at Sheppard banging his head against the wall.

"The...the last clue is matter. Or the phases of matter." He looked around quickly, afraid that stating the clue again might trigger an attack. Again, nothing happened and it was worse than the other attacks. Because this time, nothing meant Sheppard's time would run out. Time...

Time. Energy. Amplitude. Matter.

"Does that help John?" Teyla demanded, but the tickle in the back of his brain was threatening to become a full-fledged tremor. It throbbed in time to Sheppard's low bonggggs.

"Wait, wait, wait…." Rodney exclaimed, desperately trying to bring the thought into focus.

"There is no time. Rodney, please. What do we do?"

Rodney covered his ears with his hands and spun in frustration.

This whole place is a puzzle within a puzzle.

Bongggg

Even the clues that weren't about physics were about physics such as Ronon's energy and Teyla's amplitude. That was what he was trying to get into focus.

"All the clues have to do with physics," he repeated the thought out loud. "Maybe… maybe if we put them together, they'll suggest a solution to the final attack."

Bongggg

"Attack? What attack?" Ronon spat, looking around at the nothingness.

"A closed door and nowhere to go while Sheppard dies. That's as effective an attack as any other we've been subjected to."

Bonggg

"So, the clues are meant to tell us how to escape?" Teyla suggested, hesitant.

"Yes! That's what I said."

Bonggg

"Then what is the answer?"

"THAT'S WHAT I'M TRYING TO FIGURE OUT! Now, could you please stop him from making that infernal bonging so I can think?" Rodney yelled, frustration fueled by fear overwhelming what little control he maintained. "Wait!"

And with a shiver of understanding, the answer simply appeared, fully formed. It wasn't obvious. It wasn't easy, but in retrospect it was… elegant.

"I've got it! Oh, wow, I know what to do. Teyla, Ronon, stand beside the wall. When I tell you, hit it with your fists as hard as you can."

They just stared at him, eyebrows raised, skepticism etched onto both faces. "You want us to bang on the wall?" Ronon scoffed.

"Yes! Yes! It's flexible. This whole complex is a giant instrument of sorts. The elasticity of the matter amplifies the vibrations at this point. If we can excite the molecules in the wall at a specific frequency, or maybe achieve a high enough amplitude, then something will happen."

"Something?"

"Just do it."

Teyla and Ronon remained wary, but they stood and hesitantly began to thump on the wall. As it began to ring in louder and higher pitches - like overtones on a string instrument - their confidence grew and they banged harder. Rodney joined them. The whole courtyard vibrated with waves of sound that set Rodney's teeth on edge, but it was just random noise.

"Stop. Stop!" They stopped, looked expectantly at him. He wrung his hands. "We need to coordinate better. We need to set up an oscillation that aligns the soundwaves and reinforces their impact."

"Like rhythm in music reinforces the pitches, or percussion reinforces a song."

"Sure. Ok, if you say so."

"How do we do that?" Ronon snapped, as ever focused on the prosaic.

"Um, let's start by hitting together, in time."

They tried. Not being a musician, or even musical, Rodney struggled to match the pattern of the others. He was constantly ahead or behind until Teyla started to sing. Somehow, it became much easier then and their beats gained confidence. They thumped the wall in time to her song - a harvest song he realized after several repetitions of the chorus - and the courtyard again rang with noise, but it wasn't grating. If Rodney had known anything about music, he would have said that the wall sang in tune.

But it still wasn't enough. They were on the right track, Rodney could feel it, but they didn't have the right combination yet.

"Try beating different patterns, but keep them synchronized," he shouted over the wall-song.

"Different rhythms?" Teyla shouted back.

"Sure, if that's what it's called. Different rhythms."

They tried. Like before, they struggled to find patterns that were different and also in time. Teyla had stopped singing as she concentrated and Rodney was about to ask her to sing again when Ronon beat him to it. Or rather, Ronon began singing.

It wasn't a sweet, clear working song, like Teyla's, it was a marching chant, with few pitches and words that evoked strength and the emotions of war. Rodney found himself focusing on one of the frequently repeated phrases and pounded the wall in time to it. Bro-thers in arms, and sis-ters in vic-to-ry; Bro-thers in arms, and sis-ters in vic-to-ry

Teyla was pounding a pattern that sounded like Bro-thers and sis-ters and bro-thers and sis-ters

Ronon pounded vic-to-ry, vic-to-ry, vic-to-ry over and over

And each time their downbeats converged, the wall bonged with an intensity that Rodney felt he could almost see the soundwaves.

"Keep singing! Keep beating!" Rodney screamed. Ronon sang even louder. The very air seemed to shimmer and the wall was visibly vibrating. Waves and ripples in swirling patterns chased around the courtyard and under their feet on the stage. The vibrations under his feet were growing so strong, it felt like an earthquake.

And then, the wall vanished.

Technically, it melted.

With a great sploosh, the wall collapsed into liquid and was instantly absorbed by the gravel they now stood upon. There was nothing around them but a vast open field, half covered by white gravel. Mountains hovered on the horizon, purple in the evening twilight. It was utterly silent, again. Almost.

"Sheppard! Teyla! Thank God!"

Rodney turned dumbly after he regained his balance on the ground a foot from where the platform had just melted to see Major Lorne and at least two more gate teams pounding in their direction from several hundred yards away. One of the men carried a medical pack.

Rodney sank to the ground and put his head in his hands. He was shaking. His brain hurt. He would never look at a riddle again for as long as he lived.

At last, the pounding became audible, but it was the satisfying thump of boots on gravel. Rodney looked up to find several men huddled around Sheppard. Teyla was barking orders and Ronon stood nearby, flexing his arms. Readying himself to carry Sheppard to the stargate that was a half-klik away, but in sight.

He heaved himself to his feet, but before he could check on Sheppard, there was a shout of alarm. He whirled towards the spot where several soldiers were pointing.

Standing next to the podium - the only thing that remained of the maze - was an elegant old man dressed in a fantastic silk suit and draped with a gaudy, bejeweled cloak.

"Caelinus, my friend! How did you like the puzzle? I worked long on it just to please you. I hope dear Floriana is with you. I had her lovely songs in mind when I crafted the escape."

The soldiers just looked at each other, then turned to Rodney who shrugged.

"Come, come! Surely a gift as elaborate as this deserves a word of gratitude! Say something Caelinus!"

One of the soldiers gave Rodney a "go on" wave. Rodney stepped closer.

"I'm not Caelinus. Who are you?"

"Not Caelinus, eh. So he sent a servant to solve my puzzle. Well, I am disappointed. But you must tell your master that it was a wonderful maze and please encourage him to visit in person. It will reset in time. You will, of course, be beheaded if you reveal the solution."

Rodney watched closely and realized that the old man was, in fact, a holographic projection.

"I'm not a servant of Caelinus either. Who are you? Why did you build this torture chamber?"

There was a pause, as if the projector had frozen or lost its connection. "I worked long on this puzzle just to please you. I had Floriana's lovely songs in mind when I crafted the escape." Rodney recognized the phrase as almost identical to what it had said before, but it added, "I owed you something spectacular after the impressive game you set for me on my last visit. I now expect a challenge equal to my efforts upon my next visit. The fliffle is in your quad, my friend."

"Yeah, yeah. I don't care a damn about your puzzle. Who are you? What's your name?" Rodney was gaining an inkling of the situation, and it was making him angry.

"I am the Maximianus Vibius, friend of your master and lord of this region of the galaxy. Tell your master that I wish to speak to him, soon."

And with a haughty wave of his hand, the image vanished. A couple soldiers snickered at the man's name. Rodney just rolled his eyes, too tired to muster even ire. Lorne and the medic team were loading Sheppard onto a portable stretcher and Teyla was hustling them towards the stargate, which was the only place Rodney wanted to go.

"So long, Maximianus," he muttered. "Thanks for the puzzle. I'll be sure to pass on my review to Caelinus. After I blow this place to Hell."

And if John didn't survive after all their desperate efforts, Rodney thought as he turned to follow John's very grim escorts, he might just devote himself to inventing a time machine to go back and personally send good ol' Max there, too.