Castiel has never missed his wings as much as he does now. He's running as fast as he can, but the shifter is still getting further away, eventually disappearing from his sight altogether. That isn't enough to stop him, though — the shifter's still down here, and he needs to find Emma before there's no one left to find.

"Cas," Dean pants, struggling to keep up with him. "Cas, they're gone."

"No, they're —"

"Cas."

Dean puts a hand on his shoulder sympathetically, and that's all it takes for Castiel to stop. Dean's whole life revolves around saving people. He can only imagine how Dean feels about Emma, and it can't be positive, but he wouldn't let her go if he thought they could help her. If he truly thinks this is a lost cause...

"Let's keep heading this way," Dean says, gesturing ahead with his head. "I'll try to call Sam, tell him to turn around. One of us will bump into them."

"What if it's too late?" Castiel asks.

Dean sighs. "I don't know, man. I don't know."

~~

"Sam? Sam, can you hear me?"

This has to be the tenth time Dean has called him, and the third time Sam has picked up, and nothing has come of it yet. Castiel is no expert on cell phones, but he can only assume they're not meant to be used in sewers.

Fortunately, it seems Dean gets lucky this time, because after a pause, he keeps talking. "The shifter's heading your way. It has... um..." He looks at Castiel helplessly.

"Emma."

"It has Emma," Dean finishes. "We're heading back your way now." He gives Sam the chance to say something, then hangs up. "Crappy reception, but Sam's heading back this way."

Castiel just nods solemnly.

"Hey, buddy, don't worry," Dean says. "We'll find your friend."

"Or her body," Castiel says.

"Don't say that," Dean says. "She's going to be okay."

But then they see Emma heading towards them, and it's not entirely obvious whether Dean's right or wrong — or both.

As they get closer, Castiel can make out more details. There are two Emmas, which is something Castiel isn't sure he could handle even if there wasn't a shifter involved. One Emma has the other in a chokehold, her grip tight as she forces her to walk forward. She seems proud of herself, smirking as she drags the other Emma along. He can't blame her. She should be proud, taking down a shifter on her own, especially after it snuck up on her like that.

"Crisis averted," Emma calls out through the sewer, her voice echoing off the walls. "I got it while it was shifting." She glances down at the other Emma disdainfully. "It's a little creepy, trying to choke myself, but it be like that sometimes."

Castiel squints at her, cocking his head to the side. "Why didn't you kill it?"

"Dropped my blade," she says with a shrug. "It's bad enough the thing kicked up sewer water at me. I'm not shoving my hand in there."

The Emma in her grasp tries to speak, her voice muffled under the other Emma's hand. The one that's clearly in charge here just rolls her eyes as the other one struggles to get free.

"You wanna do the honors?" she asks.

Castiel hesitates. She certainly seems to be acting like his Emma, but he doesn't know for sure. He can't test his blade on her, either — if she is a shifter, she won't take too kindly to the request. How is he supposed to make sure he's killing the right Emma without letting her know that he's not sure yet?

And, just in case Castiel wasn't already aware of the possibility, the supposedly-shifter Emma manages to get the other Emma's hand off her mouth and starts talking, quicker than she ever has before. "I'm not a shifter! I swear to god, Cas, I'm not the —"

The other Emma slaps a hand over her mouth again, exasperated. "Does it really think it's fooling anyone?"

The Emma in her grasp starts fighting against her again, with tears forming in her eyes. Even if there's a good chance that she's just a monster pretending to be his friend, it hurts to look at.

Castiel chuckles awkwardly. "Yeah, really." He swallows hard. "Bring her over here. I'll take care of it."

"Cas?" Dean says quietly. "Are you sure...?"

"I know my friend, Dean," Castiel says firmly. It's a total lie, of course, but his tone is enough to convince Dean not to ask any more questions.

The dominant Emma drags the other Emma over, the supposed shifter flailing her limbs to free herself.

"Catch," Emma says, shoving the other Emma at him.

"Cas, I swear I'm me," she says, choking back a sob. "I'm not a shifter. I'm really me. I'm really — I'm me, Cas, I'm me."

Castiel pulls out his silver blades and quickly slices it across her arm, as subtle as possible. Emma doesn't even flinch, too busy begging for him to listen, but the only thing he really notices is that there's no reaction. Her skin doesn't sizzle or burn. She's telling the truth -- she isn't a shifter.

He only has one shot at this before the real shifter catches on to him. He quickly pushes his Emma out of the way and lunges toward the other, sinking his blade into her heart before she realized he had caught on to her.

And it's dead.

"Oh my god," Emma whispers, staring at it in horror. "Oh my god. Oh my..."

"Hey." Castiel puts a hand on her shoulder reassuringly. "Hey, you're okay. I knew that wasn't you. I wouldn't stab anything with your face unless I knew it wasn't you."

"But — it —"

"You're okay," Castiel repeats, though it doesn't seem to calm her as much as he had hoped — or at all — so he does the only thing he can think of. He wraps his arms around her and pulls her into a hug.

For a moment, Castiel thinks he's making it worse. Emma starts sobbing, harder than before, and he debates letting go. But then she hugs him back, squeezing him as though her life depended on it, and he realizes he didn't make her cry. Not really. He just made her feel like she could cry, like she could break down right here without warning, and he couldn't judge her.

And she was right.