For Batman to say there's no curiosity about magic, that would be false. He is naturally a person who wants to investigate everything in clear detail, preparing numerous solutions to cope with any possible situations.
Since Batman met Constantine, he has tagged him with two labels: an incurable scumbag, and as a source of information about magic.
To investigate a person thoroughly, naturally you need to figure out their daily routines and movements, and the best method for it is to follow them.
While dealing with this sort of matter before, Batman encountered certain people going to places that are a bit hard to describe. Or to state it more plainly, investigating certain people in Gotham inevitably leads him to these places.
These places invariably involve some not-so-legal activities, but their presence in Gotham would not surprise anyone.
The only exception to this rule is his psychology professor, whose life is so predictable that Batman even has a contingency plan for the possibility of him being a robot. But aside from the professor, everyone else has their little hobbies, and that includes Bruce's friends.
Harvey Dent likes to play pool and would join his court colleagues after work for a game, Gordon would go out drinking with his colleagues, or hunting in his spare time, and while Catwoman's full-time job is being a thief, when she's not stealing, she would go to dances or amusement parks. Given that all these places they have been to are owned by mobsters, some illicit deals are bound to take place there.
When investigating these people, Batman would often step in to disrupt these illegal transactions. If things went too far, he would have a talk with the boss of the joint. But these places only play a small part in the lives of these people.
For Constantine, however, these places are his entire world.
Bars, dance halls, game rooms, casinos, drug dens, Red-light District--Constantine's everyday life is to shuttle between them without ever taking a break.
During the time Batman followed Constantine, stopping the evil deals at these places Constantine frequented needed much more work than simply tracking down Constantine.
Worse still, these places often have a stench that's hard to ignore. The smell of alcohol in bars, the tobacco smoke in casinos, the heavy odor of drugs in addicts' dens. Despite preparing odor eliminators, Batman can't escape Aisha's nose.
Aisha is not an ordinary person; her senses are extraordinarily sharp. Not only does she have Night Vision Ability, her sense of smell also greatly surpasses that of an average human.
One night, Batman followed Constantine into an underground hideout where addicts congregated. Because the den was underground, Batman could not observe it from a nearby building, so he had to blend in with the crowd.
In there, he figured out Constantine's usual drug dosage and found out he was genuinely an out-and-out addict. However, Batman himself got some of that smell on him. At that time, Batman did not realize what would happen when he brought that smell home.
That day, as always, he swooshed across the courtyard, got onto the balcony with his grappling hook, and was just about to change into his clothes when he heard some noise outside the door.
Batman instantly assumed a defensive posture. Just as he was about to move towards the door, "Bam", the entire door flew off its hinges. Aisha's figure appeared outside the door. She inhaled deeply through her nose and then started crying loudly.
As it happened, Catwoman, Selina, was staying over at Wayne Manor that day. Her bedroom was right next to Batman's, and Aisha ran out from her room. Hearing Aisha's cries, Catwoman promptly dashed out.
At first, Catwoman didn't know why Aisha was crying, but as soon as she got close to Batman, she crinkled her eyebrows and retreated two steps back and asked, "Did you go to those notorious drug dens in the North District? Do you know how bad you smell right now?"
"Oh my God! That smell makes me want to puke!" Catwoman covered her neck. Holding Aisha, she backed off into the hallway as if she could not bear to be near Batman. "I know that in Gotham, you can't avoid dealing with this smell, but can't you consider that there are children in your house?"
Catwoman was very grumpy, looking quite angry. Even though she herself was a thief, she hated those drug-crazed addicts who caused damages all over the place. Plus, she had a little bit of OCD; she hated the smell of drugs.
If that wasn't enough, just a few hours ago, Catwoman had put a lot of effort into coaxing Aisha to sleep. Now the child was awoken and crying loudly.
It's like a situation when a mother who's been taking care of her child all day long finally puts the naughty kid to bed after a huge struggle. Then the father, reeking of alcohol, barges into the bedroom, making the sweetly sleeping child cry out unhappily. It's no difficult to imagine the father is in big trouble.
Moreover, the commotion woke up Dick as well. He was enrolled in a day school far from Wayne Manor, which required him to wake up early for class the next day. With this disturbance, he would undoubtedly oversleep and be late for class.
After waking up everyone in Wayne Manor, Batman had no choice but to take their complaints in the living room. If he were to face Selina, he could have explained that he goes to such places for investigation. But when it came to Alfred, Batman had no room for explanation.
Because, in old Batman's eyes, not even the sky falling down could warrant going to those kinds of places.
As expected, Batman was scolded, even though Alfred didn't chastise him in a harsh tone of a true elder, he merely advised him gently. But Batman knew very well that he'd be better off listening and then acting accordingly.
Ever since then, it's not known what kind of agreement Alfred and Aisha reached, but Aisha became a human detector, always ready to investigate Batman if he returned to the manor late at night. She'd always get close and sniff him, guessing where he'd been based on his scent.
If she detected any unpleasant odor, Aisha would instantly cry out alarmingly, waking everyone up, leading to yet another late-night confrontation with Batman.
After developing a phobia towards bats, Batman felt he had developed an 'Aisha phobia'. Even the sight of a little girl roughly Aisha's size on the street would make him want to detour around.
It's not known exactly when, but it became hard for Batman to outright refuse or act indifferent in front of the ones inside Wayne Manor.
If he insisted on his own way, he could ignore everyone's fuss, go back to his room, change into pajamas, and then sleep, only to continue the same way the next day. Neither Aisha, Dick, Catwoman, nor even Alfred could deter him.
However, Batman thought, perhaps he'd hardened himself too much towards the outside world. Every time he saw the faint lights in his own nest, he felt his coldness and obstinacy being gradually washed away.
So, like an adult taking part in a children's fairy tale performance, he'd join in with a slightly awkward and obviously forced childhoodness.
Or perhaps, he himself was the only real child in this fairy tale drama.
Batman wasn't the only one who noticed Aisha's peculiar situation. Earlier, Green Lantern Hal, who had come to Gotham due to the emergence of the Yellow Lantern Ring, had seen it too.
He also partook in the dream battle, so he knew how Aisha came to be. Now, he was faced with two problems.
The first one was whether Aisha, transformed from the Yellow Lantern Beast Parallax, would pose a threat to cosmic safety like other Yellow Lantern Demons?
The second problem was, who exactly let Sinestro, the Corps leader of the Yellow Lantern Corps, escape?
These were also the two investigative tasks that the Green Lantern Corps assigned him after Hal reported what happened in Gotham. For the first problem, Hal didn't seem to care much.
Maybe it's because the little girl transformed from Parallax looked too cute and harmless. She seemed to be more interested in finding something to nibble on than threatening cosmic safety, so Hal didn't see her as a threat.
But Hal was new to the Green Lantern Corps; he was still at the stage where he completes any assignment given to him by the Corps.
Therefore, he had to secretly keep an eye on Aisha. Fortunately, the Green Lantern Ring had many tracking features like teleportation and invisibility which saved him from being apprehended for stalking a little girl.
On the second question, Hal's investigation led him to Constantine. He was the only recent unexplained visitor to Gotham, so while tracking Aisha, Hal was also tracking Constantine.
At the same time, Batman was tracking Constantine too. So, it's hard to determine whether Hal was tracking Constantine or Batman.
In the beginning, everything went smoothly for Hal. No one in Gotham had seen someone like him, they didn't know the powers of the Green Lantern Ring. He seemed to have free reign in Gotham.
Batman, engrossed in studying magic, didn't bother with him. Green Lantern Hal's priority was considered low compared to Constantine, a magic user with unclear motives who'd fought alongside Batman against the Fear Joker.
Hal was pleased with his own progress in the investigation. He realized that the horrifying rumors about Gotham he'd seen on TV and newspapers were exaggerated.
Although there were many mobs and villains here, most of them were ordinary people without superpowers. As a Green Lantern with various superpowers, he encountered no resistance here.
Be it the most chaotic East Dock area, the North District with numerous mobster mansions, the Southern New Rich District, or the Western Old Town, he could freely roam without being targeted by anyone.
Until one day, the Green Lantern, bathed in green light, appeared at the centermost part of the central roundabout, right atop the towering traffic light pole.