This is actually the second time Batman and Spider-Man met, but this one stands on its own. It's a great story and a lot of it probably has to do with J.M. DeMatteis whose proven in the past that he knows how to handle both Spider-Man and Batman. it's a shame that there haven't been any more Batman/Spider-Man stories after this as I feel that there's a lot of potential.
Also the original one-shot was about 51 pages.
Long story short, Ra's al Ghul wants to do business with the Kingpin, so you know both Spidey and Bats have an interest in what's going on.
Kingpin turns down Ra's (who is acting through his daughter Talia) offer because he doesn't want to be involved with a terrorist organization. Vanessa Fisk, his wife, soon becomes sick.
Ra's plan is to start an earthquake that will sink Manhattan Island, the first of many natural disasters that will strike the globe. In the chaos, Ra's will emerge to offer an solitude and redemption to the world. Kingpin scoffs at her offer and tells her that any act against New York will be considered by him to be an act of war. Before she leaves, she tells Fisk that Ra's can cure his wife's cancer.
Later, concerned about his wife's wellbeing, the Kingpin decides to accept Ra's offer.
Ra's tells Fisk that they are petty annoyances beneath them, and has some of his thugs deal with them while they go on to more pressing matters. By the time Spider-Man and Batman are done, Kingpin and Ra's have escaped.
Spider-Man is knocked out in the ensuing avalanche and Batman brings him to the safety of a nearby cave.
Ra's tells Fisk that when the world is his, he will need men of like minds to administer his judgements. He tells Fisk that if he becomes his disciple, the world will be his.
Kingpin accepts his offer.
Ra's accuses Batman of getting to Talia through him, but she had nothing to do with it.
Batman offers to bring Talia back with him, but she tells him that she is by his father's side because she chooses to be.
Back in New York, Kingpin is able to elude the law by giving interpol information on Ra's. When the hideout is found, however, Ra's and Talia are missing.