Assuming you can. The reason you don't take on a mage or spirit in the middle of their fastness is because they are very much stronger there than otherwise, while you are weaker. And F9 spirit can definitely be nasty, but with edge, any kind of decent armor, and full defense, you should be safe from instant death. Now that you're no longer limited to Body x2 for armor, there's really no excuse for even mages to have less than 12 Armor or so (Lined coat, Forearm guards, helmet/ballistic mask). Sure, it won't be fun, but you should be able to avoid dying outright, which gives you as a team the chance to live, as opposed to an almost certain doom otherwise (unless, as we've said before, you're kitted out for war, or bug hunting).