v. Black In: To only be lucid in parts of specified period of time.
Blacking In: parts of the evening when one comes out of a black out for a brief period of lucidity, and your brain begins to record and process information again. Usually followed by another period of blacking out.
So suddenly I blacked in, and I was in this hotel room with 2 naked chicks. I looked in the mirror and i said to my brain "Please, please, PLEASE!!!, DO NOT black out again!!!"