The Yarrow Incident concerned a treasonous plot against Emperor Gregor of Barrayar. The civilian spaceship, the Yarrow was intended by Count Vortrifrani and an extremist faction of Barrayar's Conservative Party to be used in order to crash into the planetary and Imperial capital of Vorbarr Sultana and kill Emperor Gregor Vorbarra, but the plot was sabotaged by Lucas Haroche, of the Barrayaran Imperial Security's Domestic Affairs branch.