Star Trek: 10 Ways To Do A Crossover With Star Wars
5. A Rift In The Space-Time Continuum
Look at all the sci-fi buzz words in this one. On a routine mission to investigate some sort of anomaly in space (wait, that doesnt sound routine at all), the Enterprise-D encounters this undulating grey cloud, out of which flies the Enterprise-C from 20 years or so in the past, which immediately causes an alternate timeline where the Federation is at War with the Klingons. And Tasha Yar isnt dead!
But you know what would have been even sweeter? If the Rebel Blockade Runner from A New Hope had flown out of that rift, changing the history of Star Wars because Luke never would have gotten the stolen plans to the Death Star in R2-D2. Which in the Star Trek universe would just mean that the movies wouldnt be the same, which would suck, so they have to get the Blockade Runner back into the rift to fix the movies. But once they do, Tasha Yar is dead again. RIP Tasha Yar.