Brent Spiner

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.

Frankly, as much as I love to improvise, it hasn't been difficult to stick to the script on 'Mad Men.' The writing is so precise, and the story so carefully crafted, that I don't think there's room - or need - for ad libbing. I could never come up with dialogue as lovely as these writers do, anyway.