g man sightings

[icebox21]

can u tell me all the places were i can find the g man :smoking: i want to know were i can find him.

 

[Freyar]

The first time I noted him (outside of the beggining)

Spoiler

Is when you get into Kliener's lab and take a look at the security cams while Alyx and Kliner are talking. Hit "use" on the keyboard to cycle to the camera with the fence, eventually you will see him looking through it.