The Tower of Whispers Episode 14

Sang Li, who had taken on Yan Hui's identity, swapped her wine with water in advance, thinking she could get away with it. But the Eldest Prince arrived. The Eldest Prince brought his own wine to celebrate Yan Hui's birthday. "Yan Hui" politely declined, which displeased the Eldest Prince. He threatened "Yan Hui" with the charge of treason, leaving "Yan Hui" no choice but to drink. After "Yan Hui" drank the wine, the Heart-Binding Poison began to lose its effect. Yan Hui and Sang Li regained their senses and returned to their own bodies. Back in his own body, Yan Hui looked around the mansion and sensed something was wrong, but he was knocked out by the arriving Jun Che and taken back to Fengman House. Ying Ying sensed something was amiss and started searching for Yan Hui... (Source: iQIYI)