Double Trouble — Nancy Holder

Batman and Superman. Alien and Predator. Zatoichi and Yojimbo. The Six-Million Dollar Man and the Bionic Woman. Carol Danvers and Kamala Khan. Hercules and Xena. Iron Man and Captain America. Team-ups have been a part of storytelling for as long as stories have been told, from Enkidu helping Gilgamesh to the coming together of the Avengers.As writers of licensed fiction, one of the most enjoyable aspects is to put together various combinations of characters that don't always get together. But one thing we rarely get to do is team characters from different milieus. Sure, it happens sometimes-in 1998, Simon & Schuster published a Star Trek: The Next Generation/X-Men crossover novel, and the comics company IDW has an impressive recent history of mixing and matching some of their licensed universes-but for the most part such pairings are left to the realm of fanfiction.But what about characters who are in the public domain? The sky's the limit there.