I've talked a few times in the past about how editor Jack Schiff would take a story from Batman and run it in Blackhawk (or vice-versa). Here's another good example.
Consider these two covers:
Not hard to see the similarities; in this case the Batman story was the earlier one, appearing in the March 1959 issue of that mag, while the Blackhawk version comes from December 1960. Both tales are "dream" stories; that is to say that they did not really happen, but were a dream of one of the characters; Robin and Lady Blackhawk. Both dreams end with disaster. In the Batman tale, Batwoman's identity is exposed, thus indicating to the world that Batman must be Bruce Wayne. And the marriage of Blackhawk and Zinda ends up causing the dissolution of the team.
At the end of the Blackhawk story (after Zinda has awoken from the dream), Blackhawk asks her to go out to the movies with him, but she has a better idea: