The three sirens of Gotham City had to move – again. It seemed to happen regularly, that their not-so-humble abodes got destroyed. Ivy supposed it went with the territory: not quite villains these days, certainly not heroes, they managed to make enemies of everyone.

So it was there, at the arboretum, that she lost Harley. Not the end, but the beginning of the end.

Ivy was wandering around, exploring the grounds, when Selina came rushing in to find her. "Harley's gone."

"Gone? Who took her?" Ivy whirled around and grabbed the cat by her shoulders. "Where is she, Selina?"

"You need to take it down a notch, greenie," said Selina, removing Ivy's hands from her shoulders. "She left on her own. She was playing therapist on me –"

"Not playing," interrupted Ivy. "She is a therapist. One of the best I've known."

"Okay," said Selina, holding up a hand. "I'm not trying to insult your bestie here. I'm trying to get you to help me figure out where she went." Ivy gestured impatiently for her to continue. "I was opening up about Batman, about how there are times I wish I'd never met him, and how at those times it feels like something close to hatred."

Ivy was already halfway to the door. "Get your stupid mask if you want it. I know where she is."

They caught up with Harley at the abandoned amusement park. Catwoman and Ivy tried to reason with her, but there was a darkness to her that Ivy had never seen before. She was unreachable. Harley dosed the two of them with some version of Joker gas that Ivy wasn't immune to and stalked off, planning to take the Joker down solo.

If only she had.

As Catwoman scoped out Arkham from the top of a nearby building, Ivy fumed with impatience. She had never seen that look in Harley's eyes. There had been dark times, sure, but Harley always had the last laugh. Was her friend lost forever?

"Let's go already."

Catwoman ignored her urgency. She continued her careful scan of the perimeter and said, "No wonder you've been in Arkham so many times."

"What'd you just say?" Ivy said, dangerously quiet behind her.

Catwoman said, "I said you need to have patience, Ivy."

Patience? How dare she? When one of them was in trouble, Harley was always the first to jump into the fray. Ivy choked back her feelings and simply said, "We have our plan. Harley's in trouble. Let's go."

Then, like a cat with a laser pointer, Selina got distracted. The GCPD were converging on Devil's Square.

Ivy's only priority was saving Harley. She never wavered from that.

Harley would never abandon her friends, either. Selina had to see that. She had to make a choice.

She chose poorly.

All Selina had to say was "Ivy." And in that moment, Ivy knew. Knew she was about to leave Harley to whatever fate awaited her inside Arkham.

Ivy regarded the cat coolly and, leaving no room for misunderstanding, said, "Let me put it this way, Selina. If you walk away from this, from helping me save Harley, I will never forgive you. You will be my sworn enemy until the day I die."

They said their goodbyes. The cat left to chase whatever ball of yarn was distracting her.

And Ivy wasted no time heading for Arkham. Back to where they'd met. Back to where it all began for them. Therapist and patient, later neighboring inmates, then friends and so much more.

In a strange way, it felt like going home.

Inside, Arkham was in absolute chaos. Ivy ignored it all. She had a single goal: to save Harley. By this time, she could have been taken prisoner – by the Arkham guards or by the Joker himself – or worse.

She rounded a corner, saw the Joker about to stab some idiot in a black skull mask, instinctively shot her vines out to entrap him – and heard two words that all but shattered her.

"Puddin'! Wait!"

So it was worse, then. Worse than she could have imagined.

Ivy forced herself to put her own feelings aside – the goal was still "Save Harley," even if some insanity had driven her back into the arms of that madman.

Harley actually yelled at Ivy to put him down – three times.

Ivy thought maybe, just maybe, their friendship was strong enough to withstand Harley's Joker fixation. She spoke sternly to Harley: "Listen to me! We've been friends a long time. But if you don't come with me, that friendship is over."

She couldn't believe they were actually having this conversation. That Harley had gone from blood vengeance back into whatever unholy power the Joker held over her, apparently within minutes.

"I saved you from him – and from yourself – too many times. I'm sick of it."

She looked directly into Harley's eyes: "So what's it gonna be? Him? Or me?"

They held each other's gaze for a long moment. Ivy took in Harley's tense posture, her sneer, the fury in her eyes not directed at the Joker (where it rightfully belonged), but at Ivy herself.

Some small part of her knew that it was already over. But she couldn't just give up. More calmly this time, she said, "I'll say it one last time, Harley. Choose. Joker. Or me."

Still no response. Was Harley stalling for time? The rest of the world disappeared around them as Ivy said, pleading now, "Harley, listen to me…we've been friends a long time. As your friend, I'm asking you to come with me…I'm begging you to wake up and stop this!"

Save Harley, save Harley, chanted the voice inside her head.

She wondered what the voice inside Harley's head was saying to her right then. Whose voice it spoke in.

Finally, Harley spoke. "Wake up?"

Maybe I'm getting through to her, Ivy thought. She said, "Yes. You are a strong woman. Capable of so much. You are not—"

And then they attacked her. The Joker, who had been worming his way free while Harley – her Harley – not her Harley anymore, she realized finally – kept Ivy busy. And Harley herself. They came at her together.

Poison Ivy would not be subdued so easily, though. Her vines knocked them both to the ground. She stood above Harley and said, hating the desperation in her own voice, "What is wrong with you? This isn't you! This isn't the Harley I know! This isn't the way you are when you're not around him."

She refused to believe it. She kept trying to save Harley, save Harley. But Harley wouldn't be saved. They continued like this for another minute or so – Ivy trying to convince Harley of the truth, Harley resisting – until Harley used the word "puddin'" again and Ivy just lost it, screaming, "Joker doesn't love you, Harley! He's just using you!"

At that, Harley looked triumphant. Ivy wasn't sure why. It made her uneasy.

She kept the Joker firmly ensnared in her vines as Harley slowly started to approach her. "What about you, Ivy? Aren't you just using me, too?"

Ivy just said, desperately, "I'm your friend, Harley!"

Harley advanced on her. "Are you? What do you get out of our friendship?" She held out her hands, weaponless yet about to inflict a devastating blow. "Tell me, Ivy, what do you get? Someone to rely on you? Someone who depends on you?"

She was close enough that Ivy could have grabbed her. Could have choked her with vines, could have silenced her forever. But instead, she froze as Harley continued her verbal assault.

"Do you like that?" purred Harley. "Or is it something deeper? Is there another reason you've been so dedicated to our friendship for so long?"

She leaned close to Ivy. Close enough to touch, close enough to kiss, close enough to whisper in her ear the words that cut through every wall of vines Ivy had built around her heart, the words that cut Ivy cruelly, the words that meant Harley had seen the truth all along and chosen to ignore it until the moment it would destroy her:

"Is it because you love me?"

Ivy froze. She actually felt something deep inside her crack.

And Harley, her dearest friend, her not-so-secret love, punched her three times in the face.

Ivy fell into a hole.

She fell forever.

When she woke up, Catwoman was standing over her, taunting her. Probably putting her back in Arkham.

Ivy didn't care.

She thought she could see Batman standing behind the cat.

She didn't care.

She lay there and let them pick her up with rough hands, pull her out of the hole that Harley had knocked her into, put her in a tube with gas that neutralized her plant growing abilities.

She lay there and thought. About nature, friendship, love, betrayal.

Above all, she thought about vengeance.

She was nature, after all – red in tooth and claw. She was Poison Ivy.

And Catwoman would learn what that meant. She had taken what once meant most to Ivy in this world. Whatever drivel she had spouted to Harley about the Batman had sent her friend here, to be lost to Ivy forever.

Ivy was beyond friendship now, beyond love. But she was not above seeking revenge.

When the stranger approached her, she had already made up her mind to kill Catwoman. His offer of a donation to the rainforest conservation fund was merely a bonus.

It was a simple enough matter to breach her cell with a seeker vine, to lower the concentration of toxins in the air so that Ivy could make her escape. Some persuasion, some carefully placed vines – she was already starting to feel like herself again.

But before she dealt with Catwoman, there was a small matter she must attend to first.

The scene replayed in her head, over and over. Ivy needed to end it. Harley's slow, mocking approach, her derisive sneer, the way her lips felt against Ivy's ear as she whispered the words that made a mockery of their lives together.

As Ivy left her cell, her thoughts were crystal clear. "Harley. She's the only true friend I've ever had. But after what she did…after what she said…I am going to kill her. Snap her like a flag in the wind."

She was beyond emotion now. This was a necessary step – a link that must be forever broken so she could return to her former glory.

Ivy entered Harley's cell. Her vines trapped Harley's arms, covered her mouth. She prepared to deliver the killing blow, switching on the light and saying, "Hello, Harley. Your turn to di–"

And then she saw the cell. The Joker leered at her from every surface, his evil grin mocking her. And she knew that this desperate artwork was a reflection of its occupant's broken mind, this girl slumped on the ground in front of her.

And the familiar refrain of "save Harley, save Harley" echoed once more in the depths of Ivy's own mind.

Memories arose unbidden. Ivy felt her resolve crumbling, her humanity returning full force, unbidden and unwanted.

"Oh, Harley," she thought. "The only human I've ever called a friend."

Their first meeting outside Arkham. Harley's hand emerging from the wreck of the rocket ship, ever a willing victim of the Joker.

"To what lengths will I go? Where are my own limits? She is the Strangler Fig. And I am the tree, choking underneath."

Nursing Harley back to health.

Fighting side by side – as villains, as good guys for a night, it had never mattered as long as they fought together.

"But without her, I would fall if I grew too tall."

God help her, she thought about Harley laughing, foam on her nose from whatever ridiculous beverage was in her mug, "What?" as Ivy gazed at her friend, the light to her darkness.

"Will she ever stand by herself? Will she ever be ready?"

Ivy brought her mind back to the present. "She is in throes of madness. She sees him, her brain flooding with adrenaline—it makes her excited, nervous—then the feelings start to fade, and she needs more. And more. She sees it as passion. She sees it as love. But it's not. It's addiction. And she's relapsing."

Ivy searched her own soul for answers. Her feelings for Harley were complicating things, as usual. She considered the options.

There was classic Poison Ivy: "I could use pheromones, alter her brain chemistry." But she wasn't sure she could do that to Harley – it would make her too much like all the other clods Ivy had manipulated over the years. No, she deserved better than that.

There was abandonment: "I could leave her behind, abandoning her to the wilds of her own mind." But even now, she knew she could never walk away from the broken girl in front of her.

There was vengeance: "I could kill her right now. Show her how red Nature can be." And five minutes ago, that had seemed like the best option. The most final, in a way the kindest. But once again, the juxtaposition of Harley's apparent weakness with what Ivy knew was a core of pure strength had crashed right through her defenses.

And there was the only real option: to save Harley, like she'd intended to do when she first broke into Arkham. Ivy thought, "There's one other option. It would require patience. Even love." Ivy looked at Harley then, for a long moment. Allowed herself to access her real feelings, just this once.

Then her eyes dropped. "Maybe I'm more human than I want to admit."

It's the choice Ivy would always make. It wasn't even a choice.

She refocused Harley's attention on getting revenge on Catwoman. She held out her hand. And together, they escaped Arkham for what might be the last time.

They retrieved Harley's costume, and for a minute it felt like old times. But they didn't speak, hardly looked at each other, avoided all physical contact. So it was a nightmarish version of old times, without the deeper connection that had always united them.

They smashed into the Penguin's hideout and made him reveal Catwoman's whereabouts.

Later, on the rooftop (yet another rooftop), Catwoman and Ivy exchanged barbs while Harley stood in silence, her mind on god knows what. Ivy let it distract her for just a moment, and Catwoman disappeared.

Finally, Harley spoke out of pure surprise: "Where'd she go? She's slippery. Like Puddin' is when he fights Bats and—"

Ivy lost her cool when Harley said the P-word, as always: "Harley! What'd I say? No talking about—" and it allowed Catwoman to get the drop on her.

She was no match for the two of them, though, and between Ivy's vines and Harley's hammer, they had Catwoman tied up in a matter of minutes.

Then the truth came out. Surprisingly, Harley was quicker on the uptake than Ivy, realizing that Catwoman was telling the truth: Batman had manipulated the three of them into living together.

Ivy resisted until Catwoman delivered the killing blow: "Did we – the three of us – did we work? Did the three of us make sense as a team? Ever?"

She was talking about the three of them, but everything she said applied just as well to Ivy and Harley. Their friendship, their…no matter, it was over now.

Ivy's head dipped the slightest amount. She felt an uncomfortable sensation in the corner of her eye, a prickle and a hint of moisture. When the rage came, it was a relief.

Enormous vines shot up from beneath the streets of Gotham as Ivy raged. "BATMAN!"

It was chaos. Utter destruction. Her giant vines uprooted entire high-rise buildings, smashing them together in Ivy's fury.

Batman arrived then, and oddly it was Catwoman who fought him. Apparently she wasn't big on being manipulated, either.

But it was the three Sirens' final conversation that held Ivy's attention. Yes, she was furious with the bat. But her rage came from a deeper place, a more personal place, and it had more to do with Harley than anything else.

The others seemed shocked at the devastation Ivy could inflict. She knew, though, that she could do so much more.

Harley shouted at Ivy, "What's wrong with you? And you call me the crazy one?!"

Ivy ignored her.

Harley tried again: "Do you know what the definition of 'insanity' is, Ivy?"

Ha, thought Ivy bitterly, reflecting on all the times she'd gone back to Harley and expected a different result. But outwardly, she snapped, "Says the one who keeps going back to be abused by Joker—"

Harley delivered what would have been a killing blow, if the events of the past day hadn't already taken so much out of Ivy. "Just because no one loves you, Ivy, doesn't mean—"

Catwoman interrupted them then, urging them to leave before Batman hauled both of them back to Arkham.

Ivy collected herself. Despite everything, her mind still whispered "save Harley, save Harley" over and over. She started to leave, calling over her shoulder, "C'mon, Harley, let's—"

And Harley stood tall. "I'm not going with you."

Ivy whirled to look at her, amidst the wreckage and the flames. She held her hammer. She looked disheveled and strong and glorious. "What? Harley–"

Harley interrupted her. "Ivy. Listen to me." She walked over to Ivy, then. Put a hand on her shoulder. Looked her in the eye and said, "I'm ready."

Ivy knew then: she couldn't save Harley this time. Harley had to save herself.

She put a shaky hand on Harley's arm, wishing she could hold it there forever, could pull Harley close and whisk her away. She felt the full weight of their lives together in that moment.

But all she could say was, "…Okay."

And as Catwoman turned to face the bat, as Gotham burned around them, Harley and Ivy walked their separate ways.

Next chapter: We return to the present! (Remember how Ivy was, like, telling all of this to Harley or something? Yeah, we're going back there!)