One Missed Call

A sort of scary thing happened today. When I picked up my phone this morning I saw that I had a missed call from a hidden number. I am pretty sure I would have heard it ring. What bothers me more is that there was a text message as well. "dont forget that even mansard roofs are slippery ;-X".  Sender unknown. 

Still maybe not that unknown after all. Or what do you say, E?