A gruesome crime has taken place in La Pedrera – Casa Milà: a burned body is found on the facade of Gaudí's iconic building. Inspector Milo Malart, previously suspended for misconduct by the Mossos d'Esquadra (Mossos of the Squadron), returns to Barcelona to find the perpetrator along with Sub-Inspector Rebeca Garrido.
Xie Huai'an, son of the Huben Army's creator, survives his family's massacre. After ten long years in hiding, he returns to Chang'an disguised as a lowly registrar, moving step by step through jianghu clashes and palace power plays in a tense battle of wits to avenge his family and safeguard the realm.