A mercenary takes on the job of tracking down a target on a plane but must protect that target when they're surrounded by people trying to kill both of them.

England, 1925. At a lavish country house party, a practical joke appears to have gone horribly, murderously wrong. It will be up to the unlikeliest of sleuths—the fizzingly inquisitive Lady Eileen 'Bundle' Brent—to unravel a chilling plot that will change her life, cracking wide open the country house mystery.