I liked this one less than I liked They Came To Baghdad, but much more than I liked A Passenger to Frankfurt. It's still a late Agatha thriller, which means that it has problems, but it wasn't awful.
"Peters said gloomily: “I suppose it always comes to the same thing in the end. A madman who believes he’s God.”
There is something so naive about Christie's thrillers - I think that early in her career, her youth and charm insulated her from the ugliness of geopolitics, and late in her career, her wealth served in the same way. It's interesting to me that the body count is often lower in the thrillers than it is in the straight up murder mysteries. She doesn't seem to even remotely grasp the actuality of the violence of espionage and political intrigue.
Destination Unknown lacks the romping charm of the Bundle Brent thrillers, or The Secret Adversary, but still requires a suspension of disbelief upon which it fails, ultimately to deliver. The main character, Hilary Craven, is likable and brave. There are wheels turning within wheels turning within wheels, but at the end of the day, the entire machine sort of breaks down.
Anyway, this is a lower tier Christie, but didn't hit rock bottom.