89-year-old spinster, Janet Stouter, takes pleasure in raking up scandals, old and new, about her neighbours. She also relishes refusing her two nephews the money they seek to bolster their businesses. When a retired glass worker gives her some arsenic to kill the rats in her garden, she hatches a plan to test them. She tells them about the arsenic and waits for them to prove themselves worthy of inheriting when she dies. Whoever attempts to kill her will be her sole heir; if both do, of course, they will each get half share of her substantial amount of savings. She does, however, make sure that her life will be in no danger.
Unfortunately, the old lady spreads word of her newly acquired poison around the village, thus laying the seeds of murderous intent in several people. She had not foreseen that several other would-be assassins will come into the frame or that one will succeed in silencing her vicious tongue forever. This is a whodunnit in the classic style of Agatha Chrisite.