Sean is shocked by the sight he is seeing and takes some time to get his bearings together. Luckily, the approaching things are not very fast...

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Sean is stunned and will remain so for a total of 4 seconds. The militia men react differently, but the details depend on their respective Wills. Not sure when they are able to see what is happening (they have no night vision aids) and thus when the effects start. If they take long enough to notice it, maybe we will be already in combat by that time, not sure if that gives a +5. Bart in the cabin will probably take some time to notice that the things are amiss, after which he will fail his fright check, unless +5 for being already "in combat", because by that time shooting will likely start.