You are currently trapped inside a phone booth. When you pick up the receiver, the number “99” appears on the display, and a countdown begins. From among the vast number of flyers covering the walls on all four sides, find and peel off two flyers with exactly the same design that aren’t overlapping.

Player counts over time, as we observed them.
Source: Steam Web API, ISteamUserStats/GetNumberOfCurrentPlayers. Full methodology