走ㄗㄡˇzǒu內ㄋㄟˋnèi線ㄒㄧㄢˋxiàn

巴結或親近有權勢者的眷屬或親信，進行某種行動。《二十年目睹之怪現狀·第八八回》：「但恐卑職一個人辦不過來，不免還要走內線。」

英insider contacts, via private channels, to seek influence with sb via family members (possibly dishonest or underhand)