It is amazing how just reading the daily news can give rise to plots for the next book. I was reading that the Eden Project has withdrawn from sale jewellery made with the rosary pea, sometimes called Crab's Eye peas. It turns out that the toxin contained in the peas is 75 times more toxic than the feared Ricin made from Castor Oil beans. Sometimes these peas have been found in ethnic baby rattles!
Ideal stuff for the bad/good heroine in my next book. The peas can be purchased openly through the internet, including Ebay!