"We're too late." Piper had called Leo back from the Elders and he had orbed Xander and Cole and Cordelia had orbed Piper and Phoebe to Sunnydale, while Booth had been calling the leader of the team stationed in Sunnydale to let them know they were coming. After all, you can't drop in on demon hunters unexpectedly and not risk getting dead as a result.
"The crypt's been searched." Xander and Cordelia had approached while the others kept an eye out for any demons. Vampires were still drawn to the Hellmouth energy and there were both demons and humans that wanted to open it. It still being day meant no vampires to worry about, but demons were a definite possibility.
"There are people heading this way." Cole called out.
"Keep your hands where they can see them." Xander called back as he and Cordelia exited the crypt. "They're part of the team stationed here. Since their job is to keep people away from the Hellmouth and keep anyone or anything from trying to open it, they are authorized to kill to do that." He demonstrated.
"Agent Alexander Harris, F.B.I. and the Charmed Ones and allies." He called out to the four figures approaching.
"Authentication code." One called back and he and Xander exchanged some incomprehensible codes.
"They're going to check us, let them." Xander told the group. "They take security very seriously here, they have to."
"Special Agent Booth called to gives us a heads up and we were dispatched from base to meet you." The team leader told Xander. "Did you find what you were looking for?"
"No, it looks like it was actually worn around Gleaves neck and why the Hell he wanted it in the first place or would be buried with it are nagging questions that I don't think we're going to get answers to." Xander answered. "But it was torn off his remains, the coffin lid was shoved off and the door of the crypt was still locked so the demon probably teleported in and right back out, easy peasy."
"We can't be everywhere at once unfortunately." Allen Carson, the team leader, shook his head. "We have to guard the Hellmouth, patrol the town and guard Dr. Brennan's people who are still digging up people's homes and the woods and the forest, basically working their way through the town finding remains. Thousands of people disappeared here over the last century, she's determined to find as many of them as possible and give their family's some answers."
"I know. We've got to get back to San Francisco, we already know the Source is gunning for these ladies and I doubt he's going to wait now that he has his little trinket. We need to be prepared."
"Good luck." Allen answered and watched as the group orbed away.
"Wow, the Charmed Ones." One of the men muttered. "Beautiful and deadly, I'm glad they're on our side."
"You and me both." Allen answered. "Come on, we need to get Dr. Brennan's people to cover and reinforce the guards on the Hellmouth, just in case this idiot survives and is a sore loser."
"If I can't rule the world, you have to be enslaved to other demons, kinda thing?" Another joked.
"Scorched earth isn't just a human concept." Another muttered grimly.
As the Charmed Ones returned to San Francisco and began considering additional ideas for battling the Source and not knowing how long they had to prepare before he attacked, the Seer was finishing her modifications to the Amulet of Balthazar. Unlike the Source, she knew exactly what its purpose was and how it worked and it was absolutely perfect for her goals. When she finished, she took it to the Source. Loyal minion that she had been for thousands of years to various Sources, he had no clue of the treachery she was planning.
"It draws magical energy to itself, my Lord." She told him as she handed it to him. "Which means every time they use their powers against you, it will draw the power. You can pull the gathered power from it, strengthening yourself."
"Use their own power to make myself stronger. And Balthazar wasted its potential by feeding on his vampire worshipers? He was a fool." The Source slipped the chain over his head and let the Amulet settle against his chest. "Too bad you didn't discover its location sooner, I could have saved myself the trouble of sending various demons that proved inadequate to the task and simply attacked them myself. No matter, soon it will be over and the greatest threat to our kind will be ended, forever. No more Charmed Ones and no children to continue their line." He teleported out feeling very smug.
"If I'd given it to you sooner, it wouldn't have suited my purposes." The Seer murmured. "I needed Belthazor vanquished and the Charmed Ones Bond in place in order to make my plan work. After all, they've never been more powerful than they are now. Which will help me enormously." She smiled serenely.
When the Source flamed into Halliwell Manor he expected to find four people, the four he considered a threat. The three Charmed Ones and their whitelighter, who could heal them of anything short of death. The Seer had never bothered to inform him that they knew the Slayer, who's power was enhanced physical strength, not Magic or a necromancer who favored shotguns.
But then she also hadn't told him she'd reversed what the Amulet could do. Instead of drawing power to it for him to access, it drew his power away and unknown to either the Source or the Charmed Ones and their allies, transfered it to the only person in the room with latent demonic genes, Cole Turner.
Because it's normal purpose was to draw energy from demons to empower demons, not to or from witches, who were human.
Inside its new host, the essence of evil that the Source actually was, transfered along with the power, began taking control of its new host. Fortunately for the Seer, it retained no memory from any of its previous hosts.