Ten seasons with at least 9 time-travel episodes:
Chloe: When you were a baby. Clark, if you really are in trouble on Krypton, you’d better find a way to get there, and soon, or. . .
Clark: I’ll never have existed.

Variants

(1)
  1. Smallville by Alfred Gough and Miles Millar (3 March 2004).
  2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . written by Alfred Gough