RIGHT
You want your reset button? Here it is...
The 22nd century Borg finally get here from the Delta quadrant, just after the Earth-Rommie war. Seeing the new Federation as slightly inferior, they begin diplomatic relations. 22nd century Borg are a bit nicer than 24th century Borg, however they still don't quite understand "NO". After a long battle where Enterprise chucks slow drone after slow drone at the Borg Spear (yes, S-P-E-A-R, kinda long and pointed, like a rocket) pursuing them, Skip devises a way to turn the warp engines into a temporal vortex by routing all power through the Suliban Cell ship. The resulting vortex destroys the Spear, but they cannot stop it. It rapidly expands, destroying Enterprise, the Federation, alpha quadrant, and the entire universe in that timeline. Other quantum realities go relatively unaffected, however, at the end of the episode we'll see a scene where Guinan has to leave 10-Forward on the Enterprise-D because of a splitting headache.