Finally, an episode that takes full advantage of the flash-sideways and properly illustrates everything viewers love about Lost. 'The Substitute' is the type of episode that I expect from the final season.
The Candidate
The idea of the candidate is further explained by Not-Locke. Evidently, Jacob has been looking for a replacement to protect the island, and in doing so has developed a sequence of numbers that pertain to certain individuals in the world. You guessed it, Sayid, Jack, Hurl...