From The Longbox : Batman #441
If there is one really important thing this issue shows us is that Two Face actually spends time planning crimes based on the number two, and wonders how easy batman will regard it. Not only that, but Batman stands around thinking how to trick Two face into going after something he has to offer. I dont know if it is the most contrived scene I have ever encountered, but it actually does have to happen for the books we have seen to be puled off.
That is one scene, and there are others in the book. Including the out of nowhere scene where we discover Dick Grayson and Tim Drake has a previous encounter. That being said, once again, it is one of those writers helpers that gets someone out of trouble without ever thinking. See, Tim met Dick when Dick was a boy in the Circus, and apparently in all the world, he is the only one who has put together that Bruce Wayne got a ward. Then soon after, Batman got a Robin.
See that is the leap the book asks me to make, that honestly Oh, and as far as the other thing goes well, Batman set up a sting for Two Face at the exact same time Two face set up a trap involving twins. Yup, at the EXACT SAME TIME.
Anyway, realizing Batman needs help, Dick Grayson decides to blow the entire secret, and leads the stranger Tim Drake into the Batcave. Now I know he ends up being Robin. We all do. At the time however, Dick did not, and down he goes anyway. So Dick is dressed as Nightwing, when Tim comes up and tells him no. Batman doesnt need Nightwing, he needs Robin.