In the early morning of the next day, before the sun even rose, Eisen had Melissa's bees spread the fake explosives all throughout town. And since the particular bees in question were a kind that was able to change its color and pattern to fit other surfaces, they could make sure that the fake explosives couldn't be found that easily without Eisen wanting them to be found.
The actual raid gathering was set for the sunrise, although it would probably still take a while for everyone to properly gather. There were a lot of people that wanted to take part in the raid, after all.
He was watching all of the groups gather down in the town, although he felt all of this was a rather idiotic choice. They had placed weaponry along the spirals to fight Ailren, meaning that they were literally planning to turn the town itself into the place the raid was supposed to happen. It was like they were trying to trap Ailren down there so that he couldn't fly away.