Plump frowned deeper, taking position by Puffy again as they progressed through the single exit.  So it went for two further chambers; aside from an interesting edged formation in the basalt, hints of other encroaching ores, or occasional broadening and narrowing of the path of ice following their descent, nothing special was found.  All the while the coppery smell grew more noticeable, and it was accompanied by one other thing just shy of the fifth chamber.