Strange, rhymed advertisements in the TIMES unsettle three London gangsters - and rightly so, because soon the first of them are killed. The mysterious killer also catches a shady lawyer. Higgins and Lane find out that the key to the crimes is an unsolved diamond heist from jeweler Bolden. It looks like those involved are fighting over the loot. Eventually, it turns out that the "robbery" was actually a set-up insurance scam that Bolden was personally behind and that killed his employee. Shortly before the last survivor is sent to the afterlife, Higgins and Lane are able to confront the "invisible" murderer.
Unfortunately the movie Die unheimlichen Briefe is not yet available on HBO Max.
| Writing | Peter Jürgensmeier | Writer |
| Writing | Florian Pauer | Writer |
| Directing | Wolfgang F. Henschel | Director |
| Production | Alexander Binder | Production Driver |
| Camera | David Slama | Director of Photography |
| Lighting | Dietmar Haupt | Gaffer |
| Costume & Make-Up | Uli Simon | Assistant Costume Designer |
| Lighting | Marco Teuchert | Electrician |
| Costume & Make-Up | Hasso von Hugo | Makeup Artist |
| Costume & Make-Up | Nina Büttner | Wardrobe Master |
| Sound | Andreas Walther | Sound |
| Camera | Glenn König | Assistant Grip |
| Production | Norbert Mentrop | Production Driver |
| Production | Maike Creteau | Production Secretary |
| Production | Horst Wendlandt | Producer |
| Sound | Stephen Keusch | Music |
| Production | Angela Marquis | Casting |
| Lighting | Ralf Prokopp | Electrician |
| Art | Wolfgang Roeder | Set Decoration |
| Costume & Make-Up | Annett Schulze | Makeup Artist |
| Camera | Dariusz Brunzel | First Assistant Camera |
| Visual Effects | Michael Bouterweck | Special Effects Supervisor |
| Crew | Georg Armin Sauer | Stunt Coordinator |
| Editing | Sabine Brose | Editor |
| Directing | Claudia Beewen | First Assistant Director |
| Art | Marcus Berndt | Property Master |
| Costume & Make-Up | Anette Tirler | Wardrobe Master |
