“I can't get over how small you are!” This article is a stub. As such, it is not complete. You can help Portal wiki by expanding it.
Map: sp_a3_transition01.bsp Title: PotatOS
This is the forty-first level of the game, and takes place within the Aperture Science Enrichment Center, Pump Station Beta and some dilapidated Aperture Science offices. Goo is present in this level as its main hazard. This level also reunites the player with GLaDOS, who accompanies the player throughout the rest of the game. This and the following levels were built later, in the 1970s, and Cave Johnson's recordings are much more cynical and sarcastic than those in the previous levels from the 1950s.