Effervescent Valley
I went over what happened earlier, and I realised that I'd automatically put the HALO team in a different timeline to Comrade Omega & Sasha. That's why the microphone couldn't pick any thing up; there wasn't any silencing spells. Sorry.
Anyway, the spell is quite potent, though whether it's potent enough is up to you. It's not potent enough to stop the wizard's teleportation, though.
Also, Arkhosia: the archway is a portal to Riverside- it leads away from the cabin. If your character wants to sell to the wizard, they need to ring the doorbell and ignore the HALO truck.