Parallels

***** (5 stars out of 5)

Triumphant in the bat'leth tournament on Forcas III, Worf returns to a surprise birthday party presented by his seemingly deliberately culturally insensitive friends. Even in 2370, the rights to the Happy Birthday song seem to be unavailable, as they sing him 'For He's A Jolly Good Fellow' in Klingon. Troi points out to the disgruntled birthday boy how difficult it was to translate: "There doesn't seem to be a Klingon word for "jolly"."

Worf experiences sudden dizziness and the entire world is changing around him. His winning trophy now says ninth place. His memories don't match anyone else's. Was it the concussion he doesn't remember having?  But why would that change Troi's hair? Or Data's painting?

And what concussion results in a live-in Betazoid shrink for a wife?

Worf is dimension hopping, and the commonality when the shifts occur is Geordi. His VISOR is causing quantum leaps, if you will. Captain Riker and Lt. Wesley Crusher at security nod sagely along. Happens all the time.

According to blue-eyed Data, a theory in quantum physics holds that anything that can happen, does happen in alternate realities. (It's true: I read it in an Archie comic.) Worf's shuttle struck a quantum fissure which has put him out of sync.

Belligerent Bajorans attack the Enterprise during a scan of this fissure and the barriers between realities break down. More than 285,000 Enterprises appear in moments (fortunately none of them were occupying the same position). Among all of themselves they find Worf's original shuttle. Worf must head back to the rift and seal it the instant the lightning strikes the Hill Valley Clock Tower.
Then everything will be fine.

But some are not so keen on going back. Desperate to stay somewhere that still has a Federation and ideally FEWER BORG, a war-weary version of Riker fires on the shuttle. The local Captain Riker orders fire on Beardy Riker, and the poor devil's already ruined ship is destroyed. UNSETTLING!

Our Worf makes it back in one piece, and asks Our Troi to dinner. UNSETTLING!

"Parallels" is, to put it mildly, awesomesauce. Humor, terror, action and a radical new concept (assuming you didn't read a lot of comic books growing up.) It's better than any five episodes of Sliders you'd care to name.