With the Lightning Rascals, Toz, and the cats working together to keep watch over their surroundings and the two prisoners, it was highly unlikely anyone would be able to sneak up on them or that the two robed figures would be able to escape.
Since they didn't have to worry about things like that, Toz started thinking about how to fulfill his promise to Hassandra regarding how he saw her invisible string. He didn't want to lie, but he also didn't want to tell her everything regarding the miniature clone in his mind and the ability to see mana it gave him.
Eventually, Toz settled for telling her that he had recently acquired the ability to see mana. He didn't say anything about how he got it, how it worked, or if there was anything more to it. But he did tell her that it had nothing to do with his inclination, which meant that it should be possible for others to get it as well.