Sewer or Later (ボワボワ さぎょういん lit. Scorching Worker in Japanese) is the twelfth level and is the second level of the the third warp room in Crash Bandicoot 2: Cortex Strikes Back. In this level, taking place later than The Eel Deal, Crash explores Cortex Island's sewer again. This stage introduces triple-bladed fans that spin too fast for Crash to slip through unharmed. The player must take out the blades first by spinning the scrubbing bubbletrons into them.
If the player has obtained the yellow gem from the previous level, Plant Food, they can access the level's secret yellow gem path, which is a sinister series of challenging jumps simplified only by the fact that the only necessary item on the said route, a clear gem, is located early on so there is literally no reason to traverse the whole path and the players can just kill themselves after getting it. A split path later on in the main portion of the level awkwardly requires the player to take the right path just long enough to reach the ! crate, then backtrack to the left path to break the crates it created (and collect the crystal), then backtrack again to take the right path again to finish off the level.
This was the first non-boss, non-warp-room level during the development of this game. It is also the one with the most redesigns.
In the leaked beta version, this level had an extra TNT crate and two fewer Aku Aku crates.
In the E3 preview of the level, the yellow gem path was just a hole like what is featured in all the sewer-themed levels. The iron arrow crate configuration in the the route contained wooden crates in place of some of them and the path would split into two straight after that water section, with a slow-moving fan obstructing the left route. There were also no electric eels present in the water.
This is the only sewer-themed level in the game to have a Colored gem path.