Sylvia Plath's black knot

I sold this tiny art box assemblage in the shop yesterday, and it occurred to me that I had never written about it here.  The idea for it came to me late one night as I was reading my much-loved copy of Sylvia Plath's journals. I came to a passage that read:

"Cats have nine lives, the saying goes. You have one; and somewhere along the thin, 

tenuous thread of your existence there is the black knot, the blood clot, the stopped

 heartbeat that spells the end of this particular individual which is spelled

 "I" and "You" and "Sylvia". 

I don't think the piece needs much of an explanation after you've read the passage, I simply wanted to make something that could be held in the palm of my hand to represent what I had just read.