The adverb presently means "very soon." If you tell your sister that you'll be at her house presently, you mean that you're on your way.
You might say that the cookies you just put in the oven will be done presently, or describe how you were so sleepy last night that you opened a book and presently fell asleep, before you could read a single page. Presently also means "right now," as when you say that the temperature outside is presently thirty degrees. This is the older of the two meanings — a fourteenth-century sense of "at present" gradually changed to include "sooner or later."