Author's Note: The introduction of the angel here is borrowed from the series Supernatural. If you're a fan, you'll see what I mean. I love Castiel in the series, and his introduction in it is one of my FAVORITE scenes.. I wanted to take from that a bit.
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After Jen settled onto the bed and wrapped herself up in a blanket, Mark left to give her some time to nap. He was beginning to grow worried about her after this odd behavior she had just shown. However, some rest would do her well... right?

Her eyes had closed and she was now relaxed and calm, ready to drift off into dreamland until a voice broke through the silence, "Jennifer."
Jen opened her eyes again and looked up. The man was back and standing at her bedside, but Jen just shook her head and shut her eyes tightly, "Not real, not real, not real, not real..." she repeated to herself.

"I can assure you. I'm here. I'm real..." and with that, he reached out a hand and touched her lightly on the arm. She could actually feel it. Opening her eyes once more, she stared up at him, "But it can't be. Angels don't exist."

Again, the man appeared to be very disappointed, "You never did seem to have much faith, Jennifer. But please, trust this." After taking a couple steps back, he then stood very still, and the room now flashed as if there was lightning happening outside. But it was no lightning. This angel was trying to give a demonstration in order to prove himself. As her room flashed, Jen stared wide-eyed at him. HUGE black angel wings now appeared from this man's back, and when the flashing was over, he was back to normal again. Jen gaped, but still, she didn't know what to think, "But... but it can't be. This is just a dream. it has to be."

He shook his head, "If this is what it has to come down to, I guess I have no choice. Please don't panic, Jennifer, no harm is about to be done." ... "Huh? What are you-..." Jen began to ask, but there was an interruption. Mark had now stepped back in to check on her and he FROZE, but not for long. He could see the man now and grew protective, "Hey! Who are you?! Get the hell away from her!"
Quickly, Marked rushed in at him, swinging a fist, but it was caught inches before it had connected.
The angel lifted his left hand and placed the index and middle fingers against Mark's forehead. Mark's body immediately went limp and fell unconscious to the floor.

"Mark!" Jen screamed, and the angel turned back to her. "Calm down, he is only sleeping. I'm hoping you believe and trust in me now." Jen jumped from the bed and rushed over to check on Mark. It was true. He seemed to only be sleeping. "My name is Castiel..." the angel then introduced himself as Jen was knelt down by Mark and looking over him. She looked back up after the introduction. "...by the way." He finished.

There was an awkward pause.

After a couple of minutes, Jen was ready to speak up and say something but now another noise else had broken through the lingering silence instead. A knock at the front door. Jen hesitated and Castiel's head tilted as he noticed her uneasiness, "Henry wouldn't knock, Jennifer. There's no need to be afraid. You can answer it..."
His face then changed to serious as he looked toward the doorway, sensing an urgency from the visitor, "...in fact, you should answer it..."

The knock repeated, only this time, it didn't end.
*Knock-knock-knock-knock-knock-knock-knock-knock-knock-knock-etc*
Over and over.
Whoever stood outside now seemed desperate to get an answer.

Jen left the bedroom without a word and Castiel lifted Mark from the floor and placed him on the bed.

Jen approached the front door, but cautiously, and took a minute to peek out a window next to it. There stood a blonde girl who looked to be in her early 20s, around Jen's age. This girl was obviously upset since she was now basically slamming her palm against the door nonstop.

Jen now took another minute to look over her.
The girls' clothing looked pretty tattered and even burned!
Clearly she was in some distress as well as she then cried out, "Mark, please!"

Jen took a breath and decided to open the door.
The girl was ready to immediately speak, but paused when she saw that it was not Mark standing there. "...hi... does Mark still live here?" It was so clear to Jen now that this girl had definitely been through something horrific. Her hair was a tangled mess and her face dirty, as if from soot.

"Are you okay? What's happened to you?" Jen asked, sincerely concerned.
"Please, just answer me... does Mark live here...?"
She was obviously still upset and on the verge of tears.

Also, there was something familiar about her to Jen, but she couldn't quite put her finger on it at the moment.
"He does..." Jen nodded, "How do you know him?"

"I'm his cousin."

At those words, it suddenly hit Jen and she winced, "Cousin. Are you... are you Henry's sister?"
The resemblance was now obvious.

The girl nodded, fighting back tears, "My name is Connie."

Jen stepped aside, holding the door open for Connie to enter.
She stepped in quickly and looked around, "Where's Mark? It's urgent!"

Jen paused for a moment and looked toward the doorway of her bedroom, "He's uh..."
Castiel stood there now, looking out at them, but was apparently only visible to Jen because Connie did not seem to notice him. "He's... resting." Jen finished.

Connie now wasted no time in heading toward the room Mark was in, "Well we're in danger and need to do something!"

Castiel was still standing there and Connie passed right through him as if he was a ghost.
Jen had been following a few steps behind and paused at that sight, just a bit creeped out.
Noticing that she was spooked, Castiel decided to step aside to let her enter with ease.

Connie was at the bedside now and shaking Mark in an attempt to wake him, but he was not responding to anything. "Mark wake up! Hey... WHAT'S WRONG WITH HIM?!" she yelled as she turned back to face Jen.