l lost the Terrible Experiment & 8 monsters went to a Arkham street, the Terror Level went from 0 to 10 in one go, l assume l close all 3 shops but what happens to any monsters that are in the Outskirts, do they just stay there.

The outskirts get emptied back into the cup when the terror level hits 10. And yes, all 3 locations would be closed.

Thanks my friend for your help.