Thread: Darkness, Still in bed.

You had a "False awakening". It is exactly what you said, a dream about waking up. The first part ( leg grabbing ) was likely already a dream - near dream too. To take advantage of these situations it is best to make a habit of reality checking every time once you wake up for an example. General mindfulness and awareness practice also boosts your skills of noticing when you're about fall asleep and wake up, making it easier to become aware and lucid during these moments.

This 'black space' is pretty common for me.

Mostly when the LD is just starting, during false awakenings, and right before waking up from a LD.

Around two weeks ago during a partial but failed WILD attempt I suddenly awoke and found myself seemingly floating above my bed. Like you observed it was hard to tell if the Lucid dream had started or I was still in the transitional state so I made no attempt to move in fear of ending it early. While seemingly floating and being in near perfect blackness I suddenly sense a ominous presence in the room. I was very lucid and thinking clearly during this time. Suddenly I felt my leg being taken off my body, the first thought that came to mind was of a story of shamanic initiations I had read about where the person was torn apart, the next thought was alien abduction cases. The previously vague entity suddenly took the vivid form of a grey alien in my mind and continued pulling my leg so that it was completely off my body. I alternated in my mind with the thought it was only a dream, so I was very calm and simply observing in a neutral way, then feeling that it was a very creepy situation and not enjoying it much.