to pick out the salient points from a complex situation or text; to see through to the core of a matter

他的论文分析透彻，可谓是探骊得珠，精准地揭示了社会矛盾的根源。

to pluck a pearl from the black dragon (idiom from Zhuangzi), signifying obtaining something precious through great risk

此去虽危险重重，但若能探骊得珠，也不枉费这一番苦功。