A connection of the Atherton family.
Quite a distant connection, one is given to understand.
A young man with the kind of reputation one generally spends a lifetime acquiring. A lifetime of hard, steady sinning.
But recently, he has picked up the pace to such an extent that he has actually made London (which is a Very Big Place) too hot to hold him.
He arrived at Atherton Manor without warning, looking hunted, and has been In Residence there ever since.
He seems to have gone quite depraved. Could he have contracted some Dread Disease during one of his more disreputable adventures?