來無影，去無蹤 [来无－－－无踪]

Jyutping loi4 mou4 jing2 , heoi3 mou4 zung1
Pinyin lái wú yǐng , qù wú zōng

Definitions (CC-CEDICT)
  1. lit. come without a shadow, leave without a footprint (idiom); to come and go without a trace