Kirk: I've seen old photographs of this period. An economic upheaval had occurred.
Spock: It was called Depression. Circa 1930. Quite barbaric.
Kirk: We seem to be costumed a little out of step with the time.
Spock: I'm afraid I am going to be difficult to explain in any case, Captain.
Kirk: Well, Mr. Spock, if we can't disguise you, we'll find some way of... explaining you.
Spock: That should prove interesting.