Don't get on a novelist's bad side, because you may find yourself unflatteringly portrayed in her next book. That's more important if the novelist writes mysteries, for your avatar may end up deservedly dead. Agatha Christie accompanied her husband, Max Mallowan on an archaeological expedition and did not get along with Leonard Woolley's wife, so she wrote a novel in which an archaeologist's wife dies violently.
"Lovely Louise" Leidner is afraid. She's received anonymous threats, and suspects that either her late husband did not actually die in a train wreck or that his younger brother wants to avenge his death. Her devoted husband, the head of an archaeological dig in Iraq, hires a nurse, Amy Letheran, to keep an eye on her. Nurse Letheran arrives, meets the various archaeologists and support staff, and the next day finds Louise's corpse in a locked room. From here on out, it's classic Christie. Everyone has a motive, no one has opportunity, and Hercule Poirot just happens to be nearby. With Nurse Letheran filling in for Captain Hastings, Poirot spends a few days questioning the staff of the Hassanieh dig and letting the little grey cells do their work. After a second violent death, he assembles the suspects, explains why each one could and could not have committed the crime, and unmasks the true killer.
The murderer's identity is a surprise, and a bit of a risk, but the ingenious way in which the murder was committed makes up for any disbelief at the culprit's identity. I usually don't like unbelievable solutions to my mysteries, but this one was just well enough supported. Maybe it's because the characters (apart from Nurse Letheran) weren't very interesting, with the younger members of the group almost indistinguishable. A friend recently read Sleeping Murder (her first Christie), and wasn't impressed. Murder in Mesopotamia is perhaps a half-step above, but it's a bit forgettable and probably not a good choice for introducing someone to Dame Agatha.