By Ken Tucker
Updated February 25, 2011 at 04:02 PM EST

Let me just add to what Sandra Gonzalez has said over in her Spoiler Room: Tonight’s Fringe is a do-not-miss, revelatory episode, crossing time and space and allowing us to see Olivia and Peter as children. The hour is crammed with references to previous episodes while adding a great deal of vivid detail to the series’ fundamental relationships between Walter, Olivia, Peter, and Walter’s wife, Elizabeth.

I don’t want to write anything more, lest I give something away about the episode called “Subject 13.” But how much more strongly can I say this? Don’t miss it!

And you can be sure I’ll be recapping the episode here after it airs, as always.

Twitter: @kentucker