Princess Agents Episode 16

Yan Xun's mother is sent back to Northern Yan without him. Wen Yue's grandfather proposes Xing Er be given her first mission to get information from the Liang spies, who have discovered that Zhong Yu has been sent to protect and aid Yan Xun. Xiao Yu devises a plan to use Xing Er to lure Wen Yue, so they can both be incapacitated. She then visits Wen Huai's grandfather, warning him not to interfere with matters concerning Hong Shan House. (Source: frankly at MyDramaList)