Bruce returned from Metropolis with a mind full of thoughts, but he had not forgotten what he had been investigating before going there.
Bruce did not know when Constantine might leave Gotham, and he had no means of countering him. So he sped up his investigation, intending to thoroughly uncover Constantine's background while he remained in Gotham.
When Constantine had first been followed by Batman, he had not realized the seriousness of the situation and had not considered fleeing Gotham. By the time he wanted to leave, the blizzard had trapped him.
With transportation paralyzed, many of Gotham City's entertainment spots had closed down. Constantine had nothing better to do, so he started wandering all over the city.
Unlike ordinary people, the city of sin that everyone considered so dangerous felt like home to Constantine. Even in this city, there were few people more rotten than him. When a man was rotten enough, he became invincible.
He had been kidnapped by gangs, only to end up in the gang boss's bed within two days. Street punks had extorted him too, but aside from two half-dead toads, they had found nothing on him.
He had been kicked out by a landlord and slept on the streets, formed a band with some homeless people and made a little money, and been conned by a madam in the Red Light District. The next day, though, he had charmed her most popular girl right out of the business.
Constantine drifted through this city that resembled him in style yet differed from him as well, using his wildest, most unrestrained soul to make even Gotham fall for him.
That carefree life lasted only until he wandered near Gotham Cathedral.
Sensitive to occult matters, Constantine discovered the Fine Wine pool hidden beneath Gotham Cathedral. When he