It's easy to look at this picture and wonder, "why is this umbrella so special that it is locked in a glass case?" But that's before you learn it was a brilliant Soviet spy weapon:
So it was that one day, while Markov was walking to his car in London, he felt a sharp bite on his thigh. When he turned around he saw nothing, only a man who fumbled briefly with an umbrella before running off. The next day he became deathly ill, and died, as one is wont to do when becoming deathly ill. To this day no one has ever been tried for the murder.