司马昭之心路人皆知

sī mǎ zhāo zhī xīn lù rén jiē zhī

lit. Sima Zhao's intentions are obvious to everyone (idiom)

fig. an open secret

司

sī

to take charge of

马

mǎ

abbr. for Malaysia 馬來西亞|马来西亚[Ma3 lai2 xi1 ya4]

昭

zhāo

bright

之

zhī

(possessive particle, literary equivalent of 的[de5])

心

xīn

heart

路

lù

road (CL:條|条[tiao2])

人

rén

person; people

皆

jiē

all

知

zhī

to know