"Dean, no!" Sam yelled in despair as he arrived on the scene a second too late. The Shape Shifter's eyes flashed sinisterly silver as it injected a murky pink liquid into the top of Dean's arm through a frighteningly long needle. Although Dean lay unconscious in the monster's lap, his expression was troubled. Seeing the syringe had momentarily stunned Sam, but then he jumped into action, slipped his silver knife expertly from his pocket and lunged forwards, stabbing the Shifter straight through the heart through its back with an audible grunt.

As blood soaked the Shifter's current form, Sam couldn't help but feel surprise mingle with his anger since the Shifter died smiling. However, he had no time to dwell on this due to the overwhelming need to get Dean to safety. He knelt, scooping up his older brother in his arms, yet he knew he couldn't, or rather shouldn't drive him for 30 miles back to the hotel they were staying at. Sam figured that whatever the Shifter had injected his brother with would probably kill him in that amount of time.

Desperate, Sam cursed under his breath before looking towards the grimy ceiling of the Shifter's hideout and yelling, "Castiel! I really need your help… please." He glanced around the room without any sighting of the angel and though Sam had mostly expected him not to answer, he still cursed again, this time louder, as he flipped open his mobile phone in the hopes of reaching Bobby.

"Sam, you shouldn't keep in the habit of using such foul language."

Sam whipped his head towards the voice and a shadowy figure stepped towards him. "Cas?" he asked, nervous that the man was a soldier of Raphael's. The dark-haired man pointed the silver knife warily towards the figure, despite the fact he knew it would have no effect on an angel.

"Yes, it's me."

Exhaling slightly with relief, Sam continued animatedly. "Cas, it's Dean, you have to heal him. The Shifter, it injected… something… into him, he could be dying." Castiel had reached the only dingy area of light that the room provided and Sam now realised his features were deep-set in inner turmoil.

"Please Cas. He'll die." Sam pleaded, gripping the limp form in his arms even tighter. The angel of the Lord's face softened by an almost indistinguishable amount, but this satisfied Sam's anxiety.

"Alright, but first I must move him." Castiel answered, walking towards the both of them and placing a hand on Sam's shoulder. With an uncomfortably bright flash of white followed by a nanosecond of whirring noise and colour, they arrived back at the hotel. Sam stood, carefully lifting Dean with him and placed his still unconscious brother the hotel bed he had called dibs on when they had arrived there just four days earlier.

Castiel stepped calmly towards him, though he still had a troubled expression and knelt beside the bed, placing two hands on Dean's chest. Light burst out under his hands, leaving no shadow. The angel's strikingly blue eyes closed and fluttered beneath their lids as if he were searching Dean's very soul.

After about twenty seven seconds, he stopped.

Castiel rose, looking less troubled than before but now extremely confused. "I cannot heal him." He announced, causing a torrent of abuse from Sam.

"What! What do you mean you can't heal him? What, h-have you run out of angel juice again? You wouldn't risk getting cut off from heaven for us, but now you are anyway?" He shrieked hurtfully. Castiel flinched at the latter question, but gave a simple reply.

"He hasn't been poisoned. I don't know what the Shape Shifter did." The angel's eyes avoided Sam's and instead glared intently at the carpet of the hotel room. "I can't help."

Sam threw his hands up in a desperate act of giving up hope. "So that's it, then? You're going to let Dean die? Come on, Cas, you used to actually care about what happened to us."

Castiel's voice sounded coarse and more emotionless than Sam had ever heard it sound before. "I am forbidden to help. You know this."

"But this, this isn't emotional attachment, this is saving a life. Dean's life. Will you really put your orders above that?"

After a moment more in which Castiel's face revealed immense struggling, his shoulders sagged as he gave into Team Free Will's favourite choice.

Sam nodded and put his hand onto Dean's forehead. "So, if it's not poison, what is it?" He turned away. "Maybe we should call Bobby" He suggested, reaching for his phone.

"No need." Castiel retorted, and Sam noticed the blood as soon as he had said it. He turned his hand over to find a bloody piece of Dean's skin attached to his palm.