Space Hulk - a fickle mistress

The Seargent is down, but perimeter
is solid. Just how do we
advance again?

I introduced a non-gamer friend of mine to Space Hulk a few nights ago. He seemed to enjoy it. Let me clarify non-gamer as non-board gamer.  He's played Ticket to Ride once, and as far as I know played BSG once too. He seemed to enjoy Space Hulk, especially the timer aspect.