The Alienist 1x02 Web-dlmux Ita Eng 5 1 Earine File

The second episode, titled originally aired on January 29, 2018.

This is likely the "tag" or pseudonym for the individual or group responsible for the release. Episode 1x02: "A Fruitful Partnership"

In this installment, the core investigative team officially coalesces. Dr. Laszlo Kreizler and John Moore are joined by Sara Howard , the first woman hired by the NYPD, and the Isaacson brothers , who introduce then-futuristic forensic science techniques like "fingermarks".

This indicates the video was sourced directly from a streaming service (WEB-DL) and then "remuxed." A remux takes the raw video and audio streams without re-encoding them, preserving the original quality while changing the container (often to MKV).