How did Agatha Christie start writing stories?

During the First World War, Agatha Christie worked in a pharmacy. Most of the murders in her books are by poison, as she learned a great deal about the effects of different poisons during that time. Also, it's very interesting to visit Agatha Christie's holiday home in Devon (called Greenway). The similarities between the surrounding area and the settings for her novels are remarkable. Many of her stories are set in Devon, on boats, on islands, or near the coast. There are many coves, creeks and boathouses around Dartmouth, and lots of steep paths along the river and coastline. There is also a link between the Kingswear - Paignton steam train and the Orient Express. Some of the links are explicit. For example, at the beginning of And Then There Were None, the red hills are commented upon (the soil in Devon is much redder than that in the rest of the country) and in Five Little Pigs Elsa Greer is now Lady Dittisham. Dittisham (pronounced 'Dit-sam') is a village directly opposite Greenway, accessible by the Dittisham-Greenway boat, which takes passengers from one side of the river to the other. Later on in her career, after her marriage to Max Mallowan, she also set mysteries in more exotic places, possibly (probably?) as a result of accompanying her husband on his archaeological digs.