After Ciel and her mecha are trapped beneath a collapsed cave, snowflakes start to gently fall and fill the gaps between the rubble. Thankfully, Ciel's Illumina engineering suit is equipped with a state-of-the-art insulation system to keep her warm. There is still a faint, inexplicable light emanating from within her mecha, so this cave-in offers the perfect opportunity to study it without interruption. The only problem is that her mecha's interior is somewhat cramped, making it difficult for Ciel to even stretch her legs while she works.