Warp Zone, aka Directorate of State Archives

Anyone who has ever played Super Mario Bros knows about the existence of warp zones: in certain levels (such as 1-2 and 4-2), players could discover hidden areas that gave them access to  pipes which allowed the player to skip ahead to a different world, and so it would happen that you could be playing in a forest and in a second you could be in a world of clouds, or you could be in an underground brick level and would suddenly find yourself transported to a undersea level, where even a fish could kill you. These warp zones were only accessible to players that took the time to find them.

In the game of the city of Calcutta, this warp zone is known as the Directorate of State Archives that houses colonial archives. And so it is possible that you might be walking in the year 2026 and suddenly find yourself in the year 1864, with no idea how to return.