Murky/uncharted waters phrase
A situation that is unfamiliar to someone and potentially dangerous or difficult.
As I walked inside that abandoned house, I realized that I was getting into completely murky waters.
When I first visited Vietnam, I was in uncharted waters crossing busy streets.
When he first started working as a Youtuber, he entered murky waters of copyright law.
The origin of this phrase is not clear.
To decide that something is completely finished so that you can start doing something else
Finally we drew a line under the research before the deadline.