[@WanderingSpirit]: While I'm still waiting on my co-GM to discuss a few other things and smooth everything out so we can move on...

Clairvoyance doesn't work quite in that way to let you see through the fog perfectly. ^^; [@Raineh Daze] was expressing her concerns to be about this and I have to agree in this case. He might be able to make out some shadows and movement, though.

Rather, I think it might make more sense for Archer to blindfire some shots into the fog in a bid to spook Assassin rather then know precisely where she is? He can figure out roughly where Saber and Mira are to avoid them, as per his goal.