Vulcan's and Romulans are now the cruel masters of the universe and Worf is gone from the bridge of captain Picard's Flagship. Klingons are at war with the Federation which is on the brink of surrender! On closer scrutiny the USS Enterprise NCC 1701-D is a warship with Tasha Yar back at her old post as security chief. Just what exactly is going on? Data as usual explains. Apparently 'the cloud' is a temporal rift opening doorways in time allowing timetravelers to effect change in alternate universes.
At first glance all is not what it seems. Guinan's El Aurian intution senses whats wrong. The weird thing is the Enterprise-D isn't supposed to be a ship of WAR but of PEACE! She fills in the gaps for Picard who has a tough time buying her story, especially the bit about FAMLIES living on the Enterprise, LOL.
Billions of lives have been lost in a war that could have been avoided if one ship, the USS Enterprise-C had stayed where she really belonged.
Captain Garret's ship has to go back to 2344 and save Klingons in THE PAST because its the right thing to do. Its a suicide mission dooming the Enterprise-C to certain death but the Picard is desperate and Guinan is probably right.
One more Federation starship in the here and now hardly matters, but 22 years ago, a lone Federation starship rescuing Klingons at Narendra III would be considered 'a meaningful act of honor' by the Klingon Empire.
In the end Tasha Yar, Castillo and the Enterprise-C crew heroically race to their deaths giving Picard's alternate universe a fighting chance to survive but what would you do? Stay on Picard's ship or die heroically fighting Romulans?