“Let’s tempt fate”: Time Squared (TNG) vs. Timeless (Voyager)

After their mistakes get their crewmates killed, Harry Kim and Captain Picard have words with their past and future selves.

“I was driving starships while your great-grandfather was still in diapers”: Relics (TNG) vs. Flashback (Voyager)

Scotty finds himself in La Forge’s engine room on Picard’s Enterprise, while Janeway and Tuvok find themselves on Sulu’s Excelsior.

“You are the dreamer, and the dream”: The Inner Light (TNG) vs. Far Beyond the Stars (DS9)

Captain Picard and Captain Sisko each live out another person’s life, in two of the finest episodes in all of Star Trek.

“You’re out of your league”: Q Who (TNG) vs. Regeneration (Enterprise)

Humanity comes face to face with the dehumanizing nightmare of the Borg, for the first time … twice.

“We’ve got a long way to go”: Eye of the Needle (Voyager) vs. The Sound of Her Voice (DS9)

The crew of Voyager come to terms with being stranded in the Delta Quadrant, and the crew of Deep Space Nine “shouldn’t have to mourn alone”.

“I’d like my death to count for something”: Yesterday’s Enterprise (TNG) vs. Year of Hell (VOY)

In these two stand-out episodes, we take a trip into two darker timelines … and get a glimpse of the very different TV shows that The Next Generation and Voyager could have been.

“Our relationship has evolved”: Before and After (VOY) vs. Twilight (ENT)

Voyager and Enterprise explore aging and memory loss, in a couple of their best episodes.

“I Love Lucy is on tonight”: Little Green Men (DS9) vs. Carbon Creek (ENT)

We see Earth through the eyes of 3 Ferengi in the 40s, and 3 Vulcans in the 50s.

“I’m a doctor, not an historian”: The Trouble with Tribbles (TOS) vs. Trials and Tribble-ations (DS9)

The Original Series gives us a comedic classic, and Deep Space Nine pays tribble-ute with a comedic classic of its own.

“Is there a John Luck Pickurd here?”: Yesteryear (TAS) vs. Tapestry (TNG)

Young Spock learns that the needs of an injured pet outweigh the needs of its owner, and young Picard learns that getting stabbed through the heart can be good, actually.