Back in the glass temple which is the Montana University library, Sam studies the book meticulously at a desk beside the window. Sitting bolt-upright, he experiences one epiphany after another. With this book, everything makes sense: each victim, from Melanie Ripley to Joshua Wolfe, borrowed this book during their time at the university, and decided to deal with the Devil.

Sam opens his laptop and checks the dates for the appearance of meteor showers passing through the Serpens constellation. Sure enough, the showers peaked between December 18th and December 25th. Of course, once the pacts were made, the victims were given just one year to live, before they were dragged to Hell by the Hell-hounds...just like Dean...

Sam closes the laptop and gazes out of the window over the bleak, foggy city of Missoula. He is suddenly struck with another realisation. Maybe this was why Dean was reluctant to become involved in this case in the first place. Maybe he knew all along that these poor people were making deals and paying the price for it in the worst way. Maybe he didn't want to be reminded of what had happened to him...

Guilt sweeps over Sam as he stares into the distant mountain range, barely visible through the heavy mist. His heart is telling him to find his brother and apologise. But his ego is egging him on, to battle Lilith one-on-one and defeat her once and for all.

He opens the calendar on the laptop and checks the date: the 28th of December. Serpens would only be active for a few more days. Now was the time to strike. Sam grabs his bag and shoves his laptop inside. Tonight, as soon as the stars came out, he would perform the ritual and summon Lilith. But first, he would have to find the materials required.

The fog remains thick all through the day, and refuses to lift even in the late afternoon. Dean sits alone on a park bench, surrounded by the moist grey air. Blind to all around him, he lifts his head to the overcast heavens, partly in prayer.

A figure steps towards him through the fog. Dean glances down, filled with hope. His eyes narrow to distinguish the shape in the mist.

"Anna?"

Anna stands tall, red-headed and pale in the dimmed daylight. "Hello Dean."

"Where's Cas?" he asks immediately.

"Cas cannot be here." she informs him. "The angels are keeping a close eye on him. They don't want him visiting earth alone any more. Because of you."

"Me?" Dean frowns. "But I need him! I need him to help me protect the 66 seals!"

"Cas is desperate to help you, truly." Anna promises. "But he can't. And neither can I."

"Then why are you here?"

"I'm just the messenger. I thought you should know why Cas hasn't been around in a while, and why you shouldn't be angry with him. You know your anger has an impact upon him."

"But I thought angels couldn't feel emotion?"

"Those who doubt do feel." Anna explains. "Because of his growing attachment to you, he is at risk of doubt. That's why the angels aren't letting him out of their sight. But I fear things are much worse than that..."

"What do you mean?" Dean says, eyeing her sceptically.

Anna pauses and looks to the sky, although nothing is clearly visible. "Dean, do you know what a meteor shower is?"

Dean shrugs. "Enlighten me."

"Meteor showers always peak around this time. Light rapidly falls from the heaven to the earth, in the thousands. I was a meteor, Dean. And Cas may become one too. This is what the other angels fear most: desertion. Do you understand?"

Dean nods slowly, and scratches his chin. "The don't want Cas to become the next Lucifer. Or the next Anna." he smiles weakly, but receives no laughter in return.

"I know you miss him, Dean. And he cares so much about you. But that might eventually lead to his downfall. He can't risk being hunted by his brothers and sisters for the rest of his life. I know how frightening that is."

"So what do I do now?"

"You stay away." Anna orders. "You have to protect yourself from both demons and angels if you want to survive this. Don't become their puppet, Dean."

Anna turns away into the fog and vanishes from view. Dean is left alone on the park bench, talking to the winter mist. He closes his eyes and clasps his hands together.

"Cas..." he begins, feebly. "I know you're up there, somewhere, listening to this. I just wanted to say that...I'm sorry...for losing my temper with you. And...I know you can't be here right now...and you're probably too busy to listen to my whining. But...I really need your help right now. If you could just...send me some sort of sign, or something, to let me know that...yeah..."

"Who the hell are you talking to?"

Dean opens his eyes hopefully, only to see Alex standing in front of him sneering, holding an almost-drained bottle of whisky. Dean unclasps his hands, embarrassed. "Alex...what are you doing here?"

"I just had to kick your boyfriend out of my house." Alex slurs. "Can't you keep him on a leash or something?"

"He's not my boyfriend..." Dean growls. "He's my brother."

"Well whatever. I gave him the book and finally got rid of him, only to find you sitting alone in a park reciting some sort of love-letter to yourself." Alex shakes his head and staggers forward.

"Are you sure you should be out here on your own?" Dean asks, concerned.

"Mind your own business." he retorts, stumbles, and drops his bottle, so it shatters onto the concrete. He bends down pick up the pieces, putting his palms clumsily into the shards of glass.

"No, no, don't do that." Dean intervenes, pulling his carved-up hands away from the hazard. "Come on, I have some bandages in the car."

Alex looks up into Dean's smooth, kind face. "Your pick-up lines are crap, you know that?"

Dean quickly let's go of his hands and brushes them on his leather jacket, coughing with embarrassment. "Right, well, I'll just be going then..."

"What? And leave me out here all alone?" Alex teases. "Go on; lead the way."

Dean grits his teeth and strolls through the fog back to the impala, with Alex following closely behind.