What bargain did Haroun attempt to strike with the blue haired man before threatening to call the cops in Haroun and the Sea of Stories?

Haroun finds a strange little man with blue hair lurking around in his bathroom. When he opens the door, the little man disappears into thin air, leaving behind a monkey wrench. Realizing he'd forgotten to take his precious tool with him, the little man soon returns, demanding that Haroun hand it over. But Haroun's having none of it; he wants to know the identity of this most unusual fellow. He tells him in no uncertain terms that he's not getting his monkey wrench back until he tells him what he's doing in the bathroom. If he doesn't, then Haroun will call the cops.
The blue-haired man is reluctant to divulge his identity. He claims that he's on a top secret mission, and it would be more than his job's worth for him to let Haroun in on what he's up to. But realizing that Haroun's not going to back down, the little man rises up to his full height and reveals himself as Iff, the Water Genie from the Ocean of the Streams of Story.