Land Thawing Glaciers comes into play tapped. {1}, {T}: Search your library for a basic land card, put that card into play tapped, then shuffle your library. Thawing Glaciers gains substance until end of turn. Return Thawing Glaciers to its owner's hand when it loses substance.1
10/4/2004: The land brought into play does not count toward your one per turn limit because it was put into play by an effect.
10/4/2004: Because the "search" requires you to find a card with certain characteristics, you don't have to find the card if you don't want to.
9/16/2007: Substance is a static ability with no effect. Thawing Glaciers gains substance as a way to mimic its original (pre-Sixth Edition rules) functionality.