Toz and Hassandra finally made some progress in improving her magic string. But figuring out that Toz's mana vision saw the emptiness in the mana was merely putting them on the starting line. They still had to use that to render Hassandra's string undetectable for similar abilities in the future.
But at least now that they were done with that part, the others could help them. Since coming up with ideas only required a little creativity, the other Lightning Rascals and the cats could voice any thoughts or ideas they had that would help Hassandra change her string. That meant it was up to Toz and Hassandra to try out the ideas so that not even Toz's mana vision could pick up any abnormalities.
Though reaching the level where Toz's mana vision didn't notice anything amiss would probably take more time than they had, so their goal was to at least change the way Toz saw the string instead of aiming to make it completely undetectable in one go.
Happy new year, by the way :)