In the book haroun and the sea of stories, what does khattam-shud show haroun on the ship?

Answer: Khattam-Shud shows Haroun on the ship that each story in the Ocean requires its own type of poison to properly ruin it, and suggests how one can ruin different types of stories. Iff mutters that to ruin an Ocean of Stories, you add a Khattam-Shud. The Cultmaster continues that each story has an anti-story that cancels the original story out, which he mixes on the ship and pours into the ocean. Haroun, stunned, asks why Khattam-Shud hates stories so much, and says that stories are fun. Khattam Shud replies that the world isn't for fun, it's for controlling. He continues that in each story there is a world he cannot control, which is why he must kill them.

Explanation:

Iff here simplifies Khattam-Shud's explanation, as all that's needed to really end a story is to say it's over. However, Khattam-Shud is working to not just end stories by simply saying they're over, but to make them unappealing to audiences, which will then insure that they won't be told, Silence Laws or not. Think about the ancient stories around the Wellspring; they exist as an example of what happens when stories are deemed boring and not useful.