順藤摸瓜（順藤摸瓜）　

◎ 順藤摸瓜 shùnténg-mōguā

[follow the vine to get the melon —track down sb. or sth.by following clues] 比喻根據(jù)發(fā)現(xiàn)的線索繼續(xù)追究根底