Through their activities (and from the recovered Simplicity herself), Charlie and Dodger learn that the girl had secretly married a prince of one of the German states and thereby become an obstacle to a planned political marriage.
Her husband had then done nothing against his family's decision to destroy all evidence of the unsanctioned marriage, including Simplicity herself – the vicar and two witnesses to the wedding have already been killed.
This political dimension of the case (along with his celebrity status) soon have Dodger meet some of the Empire's top politicians, such as Benjamin Disraeli and Robert Peel.
The two young lovers hide a while in Somerset and then return to London, where Dodger has an audience with Queen Victoria and is offered work as a spy for the government, which he accepts as it suits his talents.
However, Pratchett had to "tweak" history a little to get the combination of persons he wanted in place: specifically, Sir Robert Peel is shown as Home Secretary, which he was under Victoria's predecessor William IV.