Want to know how to complete Operation Red Circus in Call of Duty Cold War? The sixth game in Activision’s Black Ops series of FPS games, Cold War’s campaign is all about preventing a Soviet spy called Perseus from carrying out his mission to subvert and undermine the United States, which tips the scales in favour of the Soviet Union.

As part of the campaign, you’ll be tasked with taking out Soviet Major Vadim Rudnik, who is helping Perseus to plant agents within European governments. How rude of him. The mission is called Operation Red Circus, and in order to complete it, you’ll need to select three suspects from a wider lineup of individuals. Time to play detective.

It’s not immediately obvious who you should choose, so in order to pick the correct suspects from the lineup, you’ll have to study evidence you’ve picked up over the course of the campaign. Here’s where to find the evidence you’ll need to figure it out – although be warned; there are Call of Duty Cold War spoilers ahead.

The first piece of evidence you’ll need is from the Brick in the Wall mission. After sneaking into Kraus’ apartment and evading detection, you’ll find Kraus’ Ledger upstairs in his bedroom, in the top drawer of a cabinet to the right of the bed.