In the early hours of Christmas, Sirius and James had snuck out to explore the castle. They were determined to discover secret passageways, and knew there must be some in existence. Covered by the invisibility cloak, of course, they rounded a corner and noticed something out of the window. They walked over to the window trying to peer out, but couldn’t make it out. Who else was awake at this time?
James looked through his telescope and bit his tongue hard to stop himself from laughing. It was Filch and Mrs. Norris, on what appeared to be a moonlight picnic.