The Enterprise C. floats through a temporal rift which has suddenly opened up in front of the Enterprise D. creating an alternate timeline in which the Federation is at war with the Klingons, and Tasha Yarr is still at her tactical post and only Guinan knows that this alternate timeline is all wrong! We shouldn’t be at war with the Klingons, therefore, the Enterprise C must to go back, but will this temperal rift have lasting consequences? Johan of Di-lithium Re-crystalized breaksdown one of his top favourite episodes in all of Trek.