Maybe to bring all 3 groups together, Soren could begrudgingly give Em and Adrian a lift out of the city, and while they're driving away it emerges that he needs to infiltrate the lab. Em could realise that Marita interns there (if I've understood that right), and offers to recruit her? Kind of like a "You scratch my back, I'll scratch yours" type deal.
EDIT: And if you want Soren's house to be destroyed, it could link back to the tracker in Em - the purifiers could launch an attack on his house, while they're hiding out there, after thinking they've discovered who her and Adrian are "working with".