Curious...what crawling thing made this tunnel? Filthy roaches, they are still at it? Didn't you say they were doing this a dozen diameters ago? Is it stamina...or something else?
Scylax concentrates on his Comprehend Magic skill, to see if there might something more to glean from the outside of the regio. He will scan the holes, he does not fancy thousands of cockroaches suddenly swarming out! He will also scan the roaches, are they...magic roaches? 
He will draw a circle on the floor, sufficiently large to hold both men comfortably, casting Circle of Beast Warding ReAn 5 Mastery 1 Quick Casting/+9 + _: 1D10 = [1] = 1 , bah, wasted! _: 1D10 = [5] = 5 , cast successfully.
Miklos, do not smudge the borders, do not destroy the circle! If mundane beasts (or roaches!) should get uncomfortably close, step inside, and they shall not vex you.
Andros will cast Unseen Arm ReTe 5 Mastery 1 Quiet Casting/+9 silently, but with Vigorous gestures (he is invisible), - 5 silent + 3 aura + _: 1D10 = [4] = 4 = 11, success, to move a stone into the regio, in the vicinity of the cockroaches, to see how they might react. If the stone can't cross into the regio, he will try to pick one within the regio. If that doesn't work, he will prepare to enter by casting the following:
At the edge of the regio, Andros will attempt a Spont ReVi Personal ward against magical creatures, R:Personal, D:Sun, T:Ind, creatures with Might 5 or less, extras go to Duration, and then to Penetration, : ReVi 17 + 2 Sta + 3 Aura + 1 Vigorous gestures + _: 1D10 = [5] = 5 = 28/2, 14, failure. He will rest and attempt once again:
_: 1D10 = [10] = 10, bah!, _: 1D10 = [1] = 1, no botch... rest. Andros will sigh. Must put that one in the plan, and it's so full already! Where can Arni have gone?
, this worm is dangerous! If the worm attacks, Scylax will avoid, though he will defend himself with Winter's Icy Touch PeIg 10 Mastery 2(4) Multiple Casting, Penetration/+20, which together with the arcane connections and horoscope should have an ok chance of affecting the thing (on a roll of 5, Penetration 27). Still, he's not particularly brave and does not look forward to being acidified, and he prefers to use the worm as resource, not attempt to kill it, so main strategy is avoidance.