In my Country, we are known for our jokes that you either get or you don't. Like comedians that tell a joke here, we just get it. But then they go to our neighboring Counrty and they have to explain the joke.
This is an example of such a joke (for the guy that needs an explination).
Two ***, means that during the joke you would probably be thinking that the whole Scot army was in the fog waiting for 50 guys, instead of just one Scot, but the joke is funny because instead of the whole army, there is two Scots, killing all those guys.
If you don't get it now, forget it, cause it isn't going to be funny any more.