ST:TNG:127 - "Time's Arrow, Part II" (Stardate: 46001.3) - this is the 1st episode of the 6th season of Star Trek: The Next Generation.
In this closing part of a 2 part caper, The Enterprise crew (Picard, Riker, Troi, Crusher, Geordi) enter a time portal on the planet Devedia II in order to rescue Data (who went back in time in 1890s San Francisco) and to figure out why there are aliens inhabiting this era of Earth's history. Picard and crew, with the help of 1890s Guinan and Mark Twain, learn to figure out what's happening - and what they find out surprises us all.
Trivia note: Jack London (a pioneer in new world of commercial magazine fiction, he was one of the first Americans to make a huge financial success from writing) is the bellboy of a hotel Data is staying at (and under the suggestion of Mark Twain, he should go into writing himself).
Also, a mention is made to the not-yet-happened 1906 earthquake, with one guy scoffing that there hasn't been an earthquake for 30 years, not believing one is possible in the near future.
In this closing part of a 2 part caper, The Enterprise crew (Picard, Riker, Troi, Crusher, Geordi) enter a time portal on the planet Devedia II in order to rescue Data (who went back in time in 1890s San Francisco) and to figure out why there are aliens inhabiting this era of Earth's history. Picard and crew, with the help of 1890s Guinan and Mark Twain, learn to figure out what's happening - and what they find out surprises us all.
Trivia note: Jack London (a pioneer in new world of commercial magazine fiction, he was one of the first Americans to make a huge financial success from writing) is the bellboy of a hotel Data is staying at (and under the suggestion of Mark Twain, he should go into writing himself).
Also, a mention is made to the not-yet-happened 1906 earthquake, with one guy scoffing that there hasn't been an earthquake for 30 years, not believing one is possible in the near future.