You know why you are here

From Fallen London Wiki

"One question: what's all this about? What could possibly have made you come down here?"

Begin an Ambition. Ambitions are among Fallen London's largest and most significant storylines – and you may only pursue one. Look for the four Ambitions in Ladybones Road, Spite, Watchmaker's Hill, and Veilgarden. Choose carefully: it is very difficult to change your Ambition once begun.

image is fallenlondon.png, unlock condition of one of the ambitions with subtext 'you have begun your Ambition. Don't hestitate.'