迂回曲折: with many twists and turns; with ups and downs; through twists and turns; going in a roundabout way (as in an argument); zigzag; circuitous
底细: ins and outs; exact details; unapparent details; unknown background 短语和例子弄清...的底细 get to the bottom of...; 了解事情的底细 know the ins and outs of the matter
摸清底细: get to the bottom of the story; ascertain the actual situation