Where do I go after Team Plasma attacks in BW2?

Question

Team Plasma attacked Opelucid City (Black 2) and froze up the place. I must have mashed A few too many times and now they're gone and I have no idea where to go. All unexplored towns are blocked off for increasingly implausible excuses and I don't see anything else in Opelucid city to do. I beat all the plasma grunts and some named Plasma big-shot, they took the DNA Splicer, and I beat the guy blocking the exit (but I see nothing of interest past that exit).

Where do I go after getting the 7th badge? I obviously need to go stop Team Plasma but have no idea where to go now that they've left.

Answer 1

Once you have defeated the Shadow Triad member at the gate to Route 11, your next stop should be Humilau City, where you get the 8th badge.

You can get there via the Marine Tube from Undella Town.

This means that, from Opelucid City, you (… can either fly or you …) need to take Route 11, then the Village Bridge, Route 12, pass through Lacunosa Town, take Route 13 and then arrive at Undella Town where you have to enter that blue downward gate. That's the entrance to the Marine Tube. Walking through that, you'll exit at Humilau City, where Hugh will greet you.