She invited four people over for lunch. A week later, three were dead.

https://www.washingtonpost.com/world/2023/08/09/australia-poisonous-mushroom-lunch-police/?utm_campaign=wp_post_most&utm_medium=email&utm_source=newsletter&wpisrc=nl_most 

Police suspect the victims ate death cap, or Amanita phalloides, mushrooms, one of the deadliest known mushrooms to humans. But whether the poisonings were intentional, or if the fungus is even the culprit, is shrouded in mystery.