The Winchesters' New Protege

The Lazarus Pit.

The second that Cas appears in the cavern, he feels the cold point of a blade held firm to his spine and a hand grips his throat, dragging him back.

"Who are you?" a sharp voice hisses in his ear. It's distinctly female but muffled by something – a mask, perhaps. One of the League's assassins, then.

"I need to see Ra's," he says flatly. The blade digs into his back slightly, but it's not as though she can actually hurt him. "As soon as possible."

"What business do you have with him?" There's the faintest trace of an accent in her voice. It's also extraordinarily dark in the cave – it's impressive that she reacted so quickly.

"Shiva? What are you doing?" says a voice to Cas's left – more authoritative, but softer, motherly almost. He turns his head, met by the blackened silhouette of a tall woman in a scarcely lit hallway. Her head cocks to the side as she looks at him. "Castiel?"

He has some vague memories of being down here before, but those were... His head had been wiped clean more times than he could count, but that voice. Where did he know that voice?

Then it hits him. The memory of a young girl, eyes like jewels, staring up at him. Her hand clutches his tighter. A name flickers through his mind and, before he can even comprehend it, it's echoing through the room. "Talia."

"It is you," she says, and he can hear the smile in her voice. Her head snaps up sharply. "Shiva! Release him. Immediately."

The blade is lowered and he's let go, followed by a begrudging, "Yes, Lady Talia."

"You're here to see my father, correct?" she says, turning her attention back to Cas. He nods and she turns on her heels. "This way."

She led him through a long, winding corridor, lit by burning torches dotted along the walls. Eventually, it spills out into a huge room, lined by two rows of marble pillars. Talia strides forwards, pushing past a pair of armed guards. Cas attempts to follow, but it knocked back by the guards.

"Let him through." That... that's not Talia.

An older man appears through a gap between two pillars and the guards immediately drop to one knee.

"Castiel," the man greets, nodding curtly.

"Ra's."

"What do you want, Castiel?" The corner of Cas's lip quirks at the sharpness of his voice – Ra's Al Ghul was never one to mince words and it's almost comforting to see that some things remain unchanged.

"I need to use your Lazarus Pit." Ra's visibly stiffens and Cas can hear the armour of the guards clanking behind him.

"For the boy, I presume," Ra's says, nodding. "Jason, I believe. The fallen Robin. If my memory serves, he was murdered. It was a rather... tragic affair, even by my own standards."

Cas doesn't know what the name 'Robin' has to do with Jason, but he files it away for later. "How do you know..."

Ra's looks at him wryly. "Even if I allowed you to use the Pit, there isn't any guarantee that he'll survive the process. The restoration of his higher brain functions alone could send him into shock. The mere memories of his death could cripple his mind."

"But with Sam-"

"He wasn't in possession of his soul when you brought him to me. It was still trapped in the Cage, with Michael and Lucifer. When he was healed, he had no real memories of being there. He doesn't even remember being brought to me. It was a miracle that he survived his soul being returned. The boy likely won't be so fortunate."