The Doctor burst into Giles' house. "I know why they're here!"

 Everyone looked at the Doctor. "Didn't we, um, cover this?" Xander asked.

 "Yes, but--no!"

 Buffy blinked. "Thanks. A perfect example of 'vague'. Now we can frame it."

 The Doctor shook his head. "I remembered what happened to us when we went through the Hellmouth! The aliens--they had some papers I'd stolen! I deciphered them, but I must have lost them when we got out!"

 Buffy pouted. "You remembered? Howcome I didn't get to remember?"

 The Doctor smiled gently. "You're only human, Buffy." His smile turned abruptly into a frown. "The aliens--they're here after a Nexus Crystal!"

 "And that is?" asked Sam.

 "It's what the TARDIS was reacting to before--a crystal that can focus and absorb trans-dimensional energies!"

 "Oh, good," commented Fitz. "Just what I always wanted, but the shops were out of them. They tried to pawn me off with bath salts, but those never worked as well..."

 The Doctor sighed in exasperation. "Don't any of you get it? They're trying...to steal...the Hellmouth!"

 Several blank stares were exchanged. Finally, Buffy asked, "And this is a bad thing? I say good riddance!"

 The Doctor shook his head. "They feed on monsters, remember? Monsters need to feed on people. They drain entire planets dry. If they can find the Nexus Crystal, they'll take the Hellmouth with them, unleash it on every inhabited planet they come across to manufacture their own portable larders.

 "They'll be a scourge across the entire universe."

 There was a long moment of silence. Then another one, as everyone tried to take in the idea of 'scourge across the entire universe.' Finally, as always, it was Xander who broke the silence first.

 "I just can't see E.T. as a vampire. Although I guess that big, glowing heart would be a lot easier to find and stake, huh?"

 The looks everyone else gave him suggested that silence would probably have been a better course.

 Giles spoke up. "The papers--they were the same ones that I read before the Hellmouth opened?" The Doctor nodded. "Yes, well...I didn't get a very good look at them, but they appeared to be records of the Spaniards that inhabited the area during the 1800's. Perhaps the writings I already possess contain copies of the notes?"

 The Doctor shook his head. "No need. I read the whole story; it described a Spanish expedition in 1852. Apparently they were heading south, in search of a legendary city of gold--"

 "El Dorado," Oz commented, with his usual tendency to pinpoint a fact with the minimum of words involved.

 "Precisely! They were unable to find the city, but they did locate an Exxilon spacecraft--not that they knew that, of course; they thought it was some sort of temple. But the description tallies. They plundered it for everything they could find, and returned...or nearly so, I imagine. The accounts end very abruptly, and there's some talk in there of illness...probably some sort of contamination from the ship's reactors. The Exxilons always did use very dirty technology."

 "So we're no closer," commented Fitz.

 "Well, we're a bit closer...we know that it would have been in with several relics of the Spanish occupation of these parts, for example..."

 Giles shook his head. "That doesn't help very much, Doctor. My contacts at the museum have been very vocal in the past about the cavalier treatment of authentic historical artifacts in the area. Anything worthwhile is as likely to be sold in an antique store, or passed off in an art gallery--"

 Buffy went dead white. "Art...gallery? Doctor, what did this Lexus Crystal look like?"

 "Nexus, not L--"

 "I do not have time," Buffy snapped, astonishing the group. "What did it look like?"

 The Doctor frowned. "About the size of a human fist, dark purple--deeper than amethyst--irregularly shaped...why?"

 "It's at my mom's art gallery."

 "No, Miss Summers," the man said, distantly, "it is not what we require for our purposes. We are looking for something else."

 Joyce struggled to keep the smile affixed to her face. "Perhaps if you could be a bit more specific, Mister....?" Internally, she moaned in frustration. "I'm sorry, I appear to have forgotten your name." Then in a flash, it came to her. Green! She'd known it was a color...it was just rattling her, the way he was acting.

 "Brown," he said. "Mister Brown. And we are looking for something smaller, we believe. Something...transparent? Translucent? We are sorry, the words you use, they are confusing...we have difficulty speaking them."

 Joyce nodded, her smile becoming ever more plastic. She looked around for some of the cut-glass work she'd gotten in a few days ago. "Like this?" she asked, handing him a piece.

 Mister Brown reached over, took it, and crushed it in his hand. His skin ripped to reveal greenish-black chitin, but he didn't seem to notice. "No," he said. "Too delicate. It will be something impossible to destroy."

 Joyce's first reaction was anger. "Now, listen," she said, "that piece was--" Then she noticed his--its hand. "What are you?" she asked, in a tone of shock mixed with familiarity. She'd feared something like this happening ever since she found out the truth about Sunnydale. "You're not human," she continued in a more steady tone. "I know that."

 It smiled, and its face ripped and shredded as the thing within uncoiled. "We are Alk-klar, Atriarch of the Delphignin. We seek the Nexus Crystal; we have travelled light-years to find it. You possess it; one of the teams we sent out has traced it to this location. You will deliver it to us immediately, or we will destroy you, destroy this entire building, turn this city into dust, and sift through the ashes."

 But the Doctor was already in motion himself, giving a different set of instructions. "Buffy, go with Giles and Xander to the art gallery--Sam, you go with them. You still remember how to do emergency first aid, right?" Sam nodded, silently. "Good. Willow, Fitz, Oz, you're with me. We've got to--"

 "--to what?" Buffy asked. "My mom is at the art gallery, they could be there with her now--"

 "...which is why you are going there now," the Doctor broke in smoothly. "But if they do get the Crystal, then they'll be taking it to the Hellmouth...and that means that they'll be heading for the school library. Where the TARDIS is. If we can get there before them, we might be able to head them off. Now--no more time for discussion. Let's move!" Everyone scrambled, each with their own private thoughts.

 "...wasn't sure what to do. I know I probably shouldn't have given it to him, but..."

 "No, Mom. You did the right thing. You couldn't have stopped him, and he'd have just ki...just taken it anyway. It's alright--we know where they're heading."

 "Are you alright, Ms. Summers?" Sam asked as she entered, already looking around for things to use as improvised bandages if need be.

 Joyce nodded. "Just a bit bruised," she commented. "Once he got what he was here for, he left."

 Giles nodded. "Then we should too--the Doctor's going to need help."

 This left Oz and Willow in the middle together.

 "I don't wanna worry you," Oz said, quietly, as they ran, "but the sun's gonna be down pretty soon, and, y'know...no cage, 'cause the aliens cut it up...you might wanna grab the tranq gun from Giles desk. I think you might need it."

 Willow gulped, but nodded. The two of them ran faster, trying to outrun the Doctor, the aliens...and now, too, the sun.

 The four of them almost ran directly into the doors, such was their haste, but the Doctor managed to stop himself with an almost casual disregard for the laws of momentum and fling them open. Then there was a careening race down the hallways, and finally they burst into the Library...

 The air was suffused with a reddish tint, as though a haze of blood had settled over their eyes from the exertions. In the center of the room, the Delphignan Atriarch stood, holding the Nexus Crystal over eir head. It pulsed with darkness, and blood-red lightning crackled around eir form as the Crystal sank its tendrils into the floor in a search for the dimensional energies that it could absorb. The Doctor moved as close as he dared to the display, with Oz and Fitz right behind him (in various states of exhaustion) while Willow went for Giles' tranquilizer gun.

 The Doctor, as was his wont in these situations, cried out, "STOP!"

 The Atriarch looked at him. "It is far, far too late for that," ey said. "Our race is dying, Doctor. The creatures we need to feed on are long, long gone from our world, from all the worlds of our galaxy. It is only here, on the distant end of Mutter's Spiral, that we can still find the food we need. We ask only to live, Doctor...only to survive."

 The Doctor's eyes were filled with sorrow. "You destroyed the supernatural ecosystem of your world, and a dozen others just like it with your callous hunting. You slaughtered the creatures that you needed to live on, and now, you want to unleash them on worlds that have no defenses against them. There is a balance--a design to the universe that shapes our ends. What you are doing will destroy that design to save your own lives, and I cannot allow it!"

 Alk-Klar's eyes shone blood-red now, as the Crystal's pulsing darkness increased its speed and the tendrils of lightning shot down deeper into the ground. "And what will you do?" ey asked. Eir voice rang out like thunder above the rising din.

 The Doctor frowned. "I'm going to check my watch," he said. He looked down. "And then I'm going to RUN, Fitz!" He darted for the bookshelves, dragging a startled Fitz behind him and leaving only Oz.

 But it wasn't Oz who stood there anymore. Already, his eyes had gone black-on-black, and his hair was growing, and then his nails extended into claws, and his jaws stretched and elongated, and fur sprouted everywhere as he became one, once more, with the Wolf.

 The Atriarch tried to move, but ey was rooted to the floor by the Nexus Crystal, unable to halt the process ey had started in motion. And then the Wolf leapt, and chitin crunched under its jaws even as bloody lightning coruscated up and down its form, and the Nexus Crystal was dropped and forgotten by lifeless hands as the lifeblood flowed from the last Atriarch of the Delphignin.

 And then Willow shot her boyfriend in the back with a tranquilizer dart, and it was all over.

 The guitar sang out in chords of pain and anguish, joined by a handsome young man with a rough, husky voice that seemed as much to be shouting out its words as singing them.

 "...we've been living here, up against the red--I've been feeling...I'm dead again..."

 In the Bronze, Dingoes Ate My Baby had packed them in again. Among the audience was an adoring Willow, an appreciative Doctor, and a relaxed Xander, Giles, Buffy, Sam, and Fitz.

 "He plays quite well," the Doctor shouted to Willow over the music.

 Willow nodded. "He does a lot of the songwriting, too; Devon likes the lyrics, but I think he gets creeped out sometimes."

 Up on the stage, Oz was focused only on mastering the diminished E chord, any effects of the Nexus Crystal apparently gone under the onslaught of loud rock and roll.

 Fitz whispered to the Doctor, "These blokes don't play half bad. I wonder if they need another guitarist?"

 The Doctor smiled. "We'll be leaving in the morning, I think. Sunnydale doesn't need a Doctor anymore, and I don't want to cramp Buffy's style. But I'm sure Oz wouldn't mind if you sat in for a night..."

 And on the edge of damnation, the party went on...

 THE END