Working on the hatch, Garrett can't find a way in, but he can find a few magical runes that seem to suggest a persistent message spell around the hatch.  If touched in the right order, they will enable the sending of short messages to someone inside the machine.  The device moves at a speed of about 10 feet a round, though the rock it's burrowing through looks rather solid, and it might go faster if it breaks into a more solid rock layer.