Ludwig

Seeking the disappearance's truth, John tries to decipher the notebook's code but needs a 'key'. Still infiltrating the station, he learns from DCS Shaw why ex-partner Neville was transferred. However, checking James's PC requires an access code. Lucy warned him against taking other cases, but seeing a woman distressed over her missing husband, he begins investigating. Partner Russell is reluctant, claiming no crime, but John senses something amiss on the security footage.

It's revealed the Sinclair case is linked to his brother's disappearance. Since Sinclair was a conspiracy theorist, Henry claims a dark organization is behind it, but Lucy and John dismiss him. John begins investigating a murdered church tour guide, but DCS Shaw and Chief Constable Ziegler appear, announcing a separate search. Furthermore, Ziegler wants to see John's skills in action. A nervous John deduces by treating the crime scene like a puzzle, but...

A worker falls to his death at a construction site. Though widely viewed as an accident, numerous suspicious points stand out. Unable to find a clue, John loses confidence and is swayed by others' opinions. Learning that workers routinely swap posts on their own, John unravels the trick set by the culprit. Watching John solve cases and make the news, Lucy feels frustrated by the lack of progress in her husband's disappearance investigation...

The headmaster's body is found at a prestigious school. The office was locked from the inside with a suicide note, but John and Russell quickly realize it's a setup and launch a murder investigation. There, John reunites with his former teacher, Todd, after 30 years. Also, the PE teacher's behavior brings back bitter memories. Meanwhile, Lucy and Henry track down the caller's address from a number that called James's phone.

[Season Finale] Summoned by Holly, Lucy gets caught up in a murder case and becomes a suspect. To prove Lucy's innocence, John confesses he is impersonating his brother. The murder is solved and Lucy is cleared, but John must leave the police station. He suggests Lucy and Henry move to his house for safety, but Lucy, worried about her husband, hesitates to agree. Just then, a message from James is left on John's phone...