How do I flip a video stream, making it effectively appear to run backwards.

For example, I've got a 6 second video stream.

I cut it at 2, 4, 6, so I've got now 3 seperate streams with 2 seconds each.

1-2 ; 3-4; 5-6 -> That how it'll be displayed normal.

Now what I want to do in Sony Vegas is to copy/paste and flip a selected stream. Let say:

1-2; 3-4; 3'-4' (copy/pasted); 5-6 -> Now I've got a video stream with 8 seconds.

Now I want to flip this copy pasted making it effectively run backwards.

1-2; 3-4; 4'-3'; 5-6.

The idea is I want something like a movie, it goes, and goes and goes, then a text appears "WAIT! What just happend?", then the movie goes back to second 3 (1-2-3-4-'WAIT, WHAT JUST HAPPEND?'-4-3-4-5-6.

I hope you get what I want to do in Sony Vegas.