Once...

One day I woke to find, a cat sitting beside me, it was grey, dark and had an evil glimpse in his eyes. I knew this cat. I didn't own him but I knew him, from a previous... Incident. I looked deeply into the depths of his face, I saw the features of a late friend. I turn around, look out the window but what is the grey, dark figures that appears before my eyes. I take my eyes back to the cat sat beside me. Where is he, he's not here? I look back through the pane of glass glimmering as I speak, there he is sat on the doorstep of my humble home. But how?