The air inside the lip of the basalt caldera was shockingly warm.
Where the Antarctic plateau outside bit with forty-below gales, the thermal plume rising from the volcanic rift created a micro-climate of heavy, sulfurous steam and damp, black granite. Ice clung only to the upper iron gantries, melting in continuous, greasy drops that hissed as they hit the volcanic rock below.
Bastian killed the throttle on the lead steam-sledge, bringing the six-ton vehicle to a stop on the broad stone apron overlooking the interior pit.
He pulled off his leather face mask, his dark eyes sharp, scanning the massive iron vault doors set directly into the basalt wall. The doors were twenty feet high, constructed of layered iron plates three inches thick, held fast by a massive central locking star connected to four heavy hydraulic cylinders.
