Sī mǎ Zhāo zhī xīn lù rén suǒ zhī
Sima Zhao's stratagem is obvious to everyone
fig. an open secret
Sī mǎ Zhāo
Sima Zhao (211-265), military general and statesman of Cao Wei 曹魏[Cao2 Wei4]
Sī mǎ Zhāo zhī xīn lù rén jiē zhī
lit. Sima Zhao's intentions are obvious to everyone (idiom)
fig. an open secret