take sb . by surprise
It's a Chinese idiom. Pinyin is y ǎ NQ í w ú B è I, which means to take advantage of the enemy's unprepared attack. It's from Sun Tzu Ji pian.
Idiom explanation
Said to take advantage of the enemy's defenseless when the raid.
The origin of Idioms
"Sun Tzu Ji Pian": "attack it unprepared, surprise."
take sb . by surprise
Strike from the east to the West - dōng shēng xī jī
Drinking Valley and perching Hill - yǐn gǔ qī qiū