Talk to Skier

Pure trader-screen step — no raid required. Open Skier's tab and hand in the dialogue. Skier is shaken: Kozlov was working a side angle for him, and now the trail leads to a co-conspirator on Streets of Tarkov. Note that Skier's accomplice and Anastasia (the woman from the door note) are different leads — you'll chase both over the next four steps. After this dialogue you'll be sent to Zmeisky Alley building 3, apartment 8, so make sure the Zmeisky 3 apartment key is in your stash before you queue Streets — it's flea-buyable for cheap.