ECHO's shape: It's a caltrop

Diana mentioned yesterday on Compuserve that she thinks she's seen the "shape" of AN ECHO IN THE BONE. It's a caltrop. This has sparked a very interesting discussion on Compuserve, regarding all the various meanings of the word, and what you can do with an object shaped like that. I would encourage you to check it out. Oh, and this relates back to my blog entry about Diana's strange and unusual words, because I'd never heard of the word caltrop until I read DRUMS OF AUTUMN. Remember the scene where Claire is walking around barefoot in the strawberry field and steps on something sharp?

I had stepped on some sort of cocklebur; half a dozen vicious caltrops were stuck in my bare sole, blood drops welling from the tiny punctures. Precariously balanced on one foot, I tried to pick them out, cursing under my breath. (From Drums of Autumn by Diana Gabaldon, Chapter 16 ("The First Law of Thermodynamics"). Copyright© 1997 by Diana Gabaldon. All rights reserved.)

I think this is a fascinating shape that has a lot of potential for great storytelling. Feel free to speculate here about what it means <g>, just please don't discuss anything you may have read in an excerpt. I'm still trying to avoid hearing anything about the plot of ECHO. Thanks. Also please keep in mind, this isn't necessarily set in stone! A few weeks ago, Diana mentioned a slightly different shape for ECHO. So it evolves over time, and it might change again.

UPDATE 2/6/09 6:30 pm: Diana announced today that the U.S. cover will be black with a caltrop on it. Look here for a picture of the proposed cover art. I think it looks fantastic! If you want to comment, my latest blog entry on the subject is here.