#WordWeavers 6 Aug: If your villain had to spend a day with your hero, what would happen?

I'm imagining in most stories with a hero and a villain, they do spend ~some~ time together and that it can get pretty intense. Climactic, even. But could they spend time together w/out sparks flying?

In the last thing I wrote with a hero and villain, you'd have to change the villain's status and situation a whole lot to make it be that he'd spend a day with the hero. It would be un-fun but uneventful.