Dr. Bashir: This could be a pre-destination paradox…
Dr. Bashir: I could be destined to fall in love with that woman and become my own great-grandfather.
O’Brien: You’re being ridiculous.
Dr. Bashir: Ridiculous? If I don’t meet with her tomorrow I may never be born!… You saw the way she looked at me. You can’t just dismiss this.
O’Brien: I can try.
Dr. Bashir: All right - fine! But I can’t wait to get back to Deep Space Nine and see your face when you find out that I never existed!