Ella fell into a fitful sleep after Thelma and Leon left, her fatigue born from more than just the need for the rest that would allow her to heal fully from her stab wound. It was a tiredness as much mental as it was physical. Almost five hundred years of hunting down Azazeal and his women, preventing the birth of the messiah of the fallen angels, and nothing had ever exhausted her so completely as six months as a school student.

Perhaps it was the never-ending battle she'd tired of, of holding back the inevitable all on her own. Malachi had said as much in Berlin: he was always going to be born. That meant the four hundred and forty five years of her life previous to that one, defining moment, had been wasted. It didn't matter how many times she'd succeeded in the past, or how she'd tried to gloss over her failure to emulate those successes in the here and now.

No amount of excuses about the reason she'd arrived at Medenham too late to stop Azazeal from finally siring his son could protect her from a truth that was as simple as it was unpalatable:

Ella Dee, last of the anointed ones, was a failure.

The previous day she'd been lying on her bed bleeding to death, weeping bitter tears over wasted opportunities. Her tears had been for Leon, and the time she'd wasted belittling him, pushing him away, scared because she could feel her defences dropping every time he got too close.

Their union didn't have the symmetry that had so enchanted her for a time with Malachi, whose destiny was inextricably linked with hers and yet so very different. Then there was the fact that she had five hundred years on his seventeen, and a whole heap of bloody baggage next to his clutch of GCSEs. But somehow none of it mattered. He completed her, and she needed him.

For someone who had spent half a millennium not needing anyone but herself, it was a pretty huge admission.

Today her mind, unable to rest completely while there was so much to think about, was racing over wasted opportunities of a different sort: the ones she'd had to kill Malachi but hadn't taken. The universe had presented her with those chances, over and over again, and she had wasted every last one of them. Some of them by default – Cassie taking the fatal blow meant for her son, Leon being unable to decapitate a sleeping Alex. Some of them by design. She had held the knife of Orokiah at Malachi's throat, and then given in to her own selfish desires, and walked away.

Perhaps it had been selfish, too, to spend her dying moments concerned only with Leon when there were so many other people in the world to consider. Yes, she was a killer, but her actions also preserved lives – countless more than the ones she was sworn to take. Thanks to her, there were whole generations that had got the chance to continue their lives unimpeded, never knowing that there was a battle of biblical proportions being waged on their behalf.

This generation would not be so lucky.

Regenerating skin strained across the site of her knife wound as she tossed and turned against rough bark. She barely registered the accompanying stab of pain that jolted through her like a lightning bolt. Her mind was on other matters, on the question that lay beneath every thought she had had since her final attempt to kill Malachi had backfired so spectacularly. On why it was she had become such a failure – become so fallible. Become such a faltering shadow of her former self...

"Surely you know the answer to that by now," a voice said.

She struggled up an eyelid. "Leon..?"

"Oh, don't worry. We'll get to him later."

Ella's eyes snapped open. She found herself staring into another set of eyes, belonging to a figure crouched in front of her, shrouded in silhouette. As the figure stepped back into the light, she bolted upright, uncommonly terrified by what she saw in front of her.

It was her.

Although she didn't spend nearly as much time looking at herself in the mirror as Alex or Roxanne had – unless they'd been afflicted by an outbreak of biblical boils, anointed ones had no time for vanity – there was little doubt that, minus the mirror, that was exactly what she was doing. The woman standing in front of her had the same vibrantly red hair, the same dark rimmed brown eyes, the same pale skin.

Everything, down to the corset and the bloodstained blouse beneath it, was identical.

"A demon in my own image sent to snare me," she said scathingly, once she'd recovered the use of her voice. She slid one eye to the clearing ahead of her, calculating how quickly she could retrieve the volta. "How very – creative."

The other Ella laughed. "I'm not a demon."

"Then what? An archangel?"

"Oh, what an over inflated sense of your own greatness you have, Ella. Surely you don't believe yourself so important that a messenger must be sent to reverse your decision to sever your links with the heavens?"

"Of course not," Ella stuttered. It was somewhat disconcerting to be lectured by yourself. For the first time she realised just how intimidating she could be.

"God is already amassing a vast army of light to do battle with the darkness," the other Ella continued. "What need would He have for a champion whose flesh is so weak that she wilfully defied her destiny, in favour of her own desires?"

The words drew a flicker of memory from the depths of Ella's brain. She drew herself up straighter, forcing herself to meet her double's unblinking gaze.

"Raphael."

"He told you your flesh was weak, too. And he was right, wasn't he?"

She held up a hand as Ella opened her mouth to protest, seemingly knowing what Ella was about to say and do before she did it. "Don't give me excuses. In no way do his sins compensate you for yours. You know that."

"I gave in to lust," Ella conceded, the stranger hitting her weak spots with such pinpoint accuracy that she felt a compulsion to answer its charges. "My—desire—for Malachi. It stopped me from killing him when I had the chance."

The double cocked her head to one side. "Hmm. So him taunting you about how you'd killed his mother in the exact same spot had nothing to do with it?"

"Well, a little, perhaps..." She stopped, annoyed with herself for getting drawn into it. "Does it really matter now?"

The double smirked at her from a safe distance. "Not to me."

"Who are you?" She felt her anger flaring. "What do you want from me?"

"Nothing more or less than you yourself desire. An understanding of your failings..." The doppelganger flicked back her curtain of red hair almost casually. "An admission of your culpability."

"Culpability for what?" Ella followed the double's gaze as she nodded over her head, back in the direction of Medenham Hall. Recognition dawned inside her.

"You rose from the depths of hell to hear me admit I'm to blame for the end of the world?"

"Then you do admit it."

Ella glared at the spectre in front of her, angered by its attempts to trap her into voicing the failures that had swirled so freely in the safety of her inner thoughts. Self-flagellation was one thing; admitting your mistakes was quite another. It was the first, most ancient rule of combat: do not allow the enemy to discover your weaknesses, for they are sure to use them against you.

The second, purge yourself of those weaknesses, was something she'd never quite mastered.

She opened her mouth to deny it. But the words she sought refused to obey. Others merrily trooped to her lips instead, ready to betray her secret thoughts, her secret shame.

"I – I'm to – I'm to blame."

She slumped back against the trunk of the tree, dazed, as the double continued her interrogation mercilessly, seemingly oblivious to her pain.

"You failed to kill Malachi."

"Yes."

"You failed to stop him from bringing about the End of Days."

"Yes."

"Why?"

Ella considered the question for a long moment. When she finally replied it was in calm, measured tones. She felt cool and detached, able to view what had happened and see where she'd gone wrong with crystal clarity.

"Because I squandered the best opportunity to kill Malachi I was ever going to get. Every event thereafter resulted from that one. He took me as his first succubus, making him realise the power he could exert, and with every other soul he took he grew more powerful until he was too strong to destroy. So yes...it's fair to say that the End of Days is my fault."

She looked to the ground, contrite. "The blame rests entirely with me."

"Fine words, Ella," her double said with a condescending smile. "If a little melodramatic."

She lifted her head. "That's what you wanted, isn't it? For me to admit it? To know why it happened?"

"Oh, you could go over the sequence of events until you were blue in the face, until the end of time if you wanted to, but you still wouldn't have answered my question."

"Now who's being melodramatic?"

The other Ella laughed. "Defensive, aren't you? It's a miracle anyone's ever managed to penetrate that frosty veneer. Tunnel down to the frozen heart beneath it..."

She spun on a stiletto heel and started to pace back and forth, her hands clasped behind her back like a schoolteacher. Ella's eyes strayed to the double's feet, and she realised that although it was walking like a flesh and blood being, the motion disturbed none of the leaves underneath it. They remained as still as if there was nothing there.

"Don't you find it odd that no less than three men have managed to perform that miracle in the space of a year? And then there's Thelma, of course. That suggests to me that you actually wanted to let them all in. Literally, in some cases..."

The double abandoned her pacing and sat down next to Ella. "You know what else it suggests?"

"No," she said tersely. "But I'm sure you're going to enlighten me."

"Most likely it was a subconscious decision, but make no mistake, it was a decision. Why else would you have allowed yourself to be delayed on your way to what should have been a routine dispatch of another of Azazeal's conquests? Frivolous physical pleasure isn't that hard to come by in the twenty-first century. I believe it's called a one-night stand."

"Make your point," Ella snarled.

"It suggests that you were seeking to be something more than you were. Human, Ella. You wanted to be human."

She leapt up, stung, the accusation hurting more than the sudden motion. "That's absurd!"

"So you didn't want to be human?"

"Stop trying to put words in my mouth," Ella snapped. "Who are you to presume to tell me what it is I want, demon?"

"You wanted to know why you've become such a failure, didn't you?"

Ella frowned, feeling a little uncertain, as if the double had somehow managed to rummage around in her head and steal all her secrets.

"How do you know all these things?"

The double blithely ignored the question. "Oh, I know more than you think. I know the answers."

She felt her heart thumping. "Which are?"

"It's quite simple, Ella. You became a failure when you became more like a human being than an anointed one. When you allowed yourself to want things you can't have, to be things you can't be. Friend. Lover. Soulmate. Mother..."

Ella saw red. Ignoring all the signs that had told her the doppelganger wasn't real and therefore unable to interact physically with her, much like Thelma, she sprang forward, hands outstretched like claws. With a growl she landed on the double, knocking her to the ground, and pinned her there by the wrists. To her surprise, they were as warm and as solid as her own.

"I can touch you," she said, caught off guard by the discovery. It was the ideal moment for the double to get the upper hand in their battle, but she just lay there inertly on the ground, grinning.

"If you insist." She stared lasciviously up at Ella, sitting on top of her. "Thelma would have an embolism if she saw this."

"I doubt that. Redheads aren't her type."

"But it's everyone's favourite fantasy, isn't it? If only they'd admit it. The last great taboo. Doing it with your favourite person in the whole wide world. After all, who can possibly understand you better than...yourself?"

Ella felt her grasp on the wrists loosen. She sank back, staring into the double's eyes. Her own eyes. The other Ella began to chuckle to herself, the sound echoing loudly in the silence of the empty woods.