I'm just learning Overlord 2, and I've reached the point where I get the spell to control/kill townspeople. I've controlled 3 of them like it instructed me too. But I can't figure out what to do next. I seem to be blocked on both sides by firecracker "walls", and it told me I can't get through them until I find my red minions, but I don't seem to be able to summon red minions yet. What am I supposed to do next?