Hmm... I'm not too worried about the magic's failing.  I think it's plain we'll have to fight at some point.  The magic would just be to stretch that point out as far as possible.  And the real problem with sending Mark in alone would be that he's far too vulnerable.  (We could send Kasumi in alone, using the same combinations, but she can't open locks or detect of disarm traps.)<br/><br/>In this case, a small infiltration, even if discovered, is not likely to cause a the undead to flee the building, it's more likely to pull a number of them farther inside, for a 'snack'.<br/><br/>And then, once the fight is over, the magic can always be recast, and more sneaking happen, if we're still too far away from the center.<br/><br/>Even if we had to fight our way in, since I can increase all our movement speeds, the Zombies at least will not even be an issue.