[London has asked Clemens to help him write his own life story]
Samuel Clemens: Young man, I have a maxim that I have always lived by: no one is more qualified to write your story than you are.
Samuel Clemens: I suspect that even time travelers are vulnerable to the Colt .45.
Guinan: You know an awful lot about me.
Captain Jean-Luc Picard: Hmm. Believe me, in the future, the tables will be turned.
Guinan: Do we become friends?
Captain Jean-Luc Picard: Oh - it goes far beyond friendship.
[Picard, disguised as a workman, slips a small electronic detector into a wall sconce in a hospital ward]
Dr. Appollinaire: Just what're you doing with those lamps?
Captain Jean-Luc Picard: Replacing the burners. City ordinance. Makes it safer, in case of earthquake.
Dr. Appollinaire: There hasn't been an earthquake here in thirty years.
Captain Jean-Luc Picard: [picks up his toolbox] Well, that takes care of this ward. Time to be moving on.
Dr. Appollinaire: [scoffs] Earthquakes.
[spoken in San Francisco in 1893]
Samuel Clemens: You got any passions, boy, any dreams?
Jack London: Well, I'd like to do some traveling, maybe go to sea. And Alaska - I've had the strangest notion to go see Alaska!
Samuel Clemens: That's a great idea, son, that's exactly what I would do if I were your age. Alaska, the Klondike, the aurora borealis, that's it! Follow your dreams, and write about them.
Jack London: Thank you, Mr. Clemens. You know, that is exactly what I'm gonna do.
Samuel Clemens: You do that, son.
Jack London: You'll see my name in print, too.
Samuel Clemens: I'm sure I will.
Jack London: And don't forget - the name's London, Jack London!
Samuel Clemens: [to Troi] So, this is a spaceship. You ever run into Halley's Comet?
Samuel Clemens: Don't worry, Madam Guinan. You're gonna be fine.
Samuel Clemens: Where are we? And when?
Commander William T. Riker: This is the 24th century, we're on Devidia II, and you're not supposed to be here.
Samuel Clemens: Well, it seems to me I have as much right to be in your time as you had to be in mine. I wanted to see how you've conducted my future affairs.
Counselor Deanna Troi: Your future affairs?
Samuel Clemens: The affairs of mankind.
Commander William T. Riker: But the disappearance of Mark Twain, one of the most noted literary figures of the 19th century...
Samuel Clemens: Thank you.
Commander William T. Riker: That's not supposed to happen.
Samuel Clemens: I only took advantage of an irresistible opportunity, as any good writer would.
Counselor Deanna Troi: Poverty was eliminated on Earth, a long time ago. And a lot of other things disappeared with it - hopelessness, despair, cruelty...
Samuel Clemens: Young lady, I come from a time when men achieve power and wealth by standing on the backs of the poor, where prejudice and intolerance are commonplace and power is an end unto itself. And you're telling me that isn't how it is anymore?
Counselor Deanna Troi: That's right.
Samuel Clemens: Hmmm... Well... maybe... it's worth giving up cigars for, after all.
Captain Jean-Luc Picard: I wish... I wish time would've allowed me to know you better.
Samuel Clemens: Well, you'll just have to read my books. What I am is pretty much there.
[Picard then turns towards Guinan]
Guinan: I'll see you in 500 years, Picard.
Captain Jean-Luc Picard: And I'll see you... in a few minutes.
Samuel Clemens: Any place that doesn't stock a good cigar doesn't rank high in my book.
Commander William T. Riker: I just want you to know that I have the utmost respect for the law.
[punches policeman in the face]
Guinan: Do you know me?
Captain Jean-Luc Picard: Very well.
Guinan: Do I know you?
Captain Jean-Luc Picard: Not yet. But you will.
[Clemens mentions to Data an employee of the county assayer's office Data has spoken to earlier]
Lt. Commander Data: I have spoken to several people in that office.
Samuel Clemens: Yes, I know. And in the hall of records, and in the Geological Society, and in a little-known mineral shop in Chinatown. You do get around, don't you?
Lt. Commander Data: As apparently you do, Mr. Clemens.
Samuel Clemens: I know what you say, that this is a vessel of exploration, and that your mission is to discover new worlds. That... that's what the, the Spanish said... and the Dutch, and the Portuguese...
Guinan: [seeing Data's severed head in the cavern] What's that?
Captain Jean-Luc Picard: That's history fulfilling itself.
Captain Jean-Luc Picard: We know how you move back and forth through time. My crew have returned to the 24th century to destroy your transport site on Devidia II.
Alien Nurse: Destroy it? Your weapons will only amplify the time distortion. You will annihilate your own world.
Captain Jean-Luc Picard: Captain's log, stardate 46001.3 - Everyone who should be in the 19th century is safely there, and those who should be in the 24th are here. Mr. Data has been restored to us, head and all, and Samuel Clemens will write the books he was to have written after our encounter.