Xander, it wouldnt really be like First Contact, because First Contact was more about repairing damage the Borg had done in Earths past. My idea would be more of an "Origin Story" about the Katesh, and us getting a chance to learn more about the conflict with the Iconians to understand the Katesh motives in the present day. In FIrst Contact, the Enterprise followed the Borg into the past to prevent them from altering it. We would be thrust into the past by some anomaly (Let Orrin figure that shit out, he is the science geek) and the Discovery would have to figure out a way back to the present without being detected, or altering the course of history. Perhaps we inadvertantly stop the Iconianis from banishing the Katesh, and have to figure out a way to make it work...i see plenty of potential story lines we could take from that point.