The Wild Lord (London Scandals, #1)

1822.
Given up for dead, Edward Northcote, heir to the earl of Briarcliff, has been dragged home and displayed before all London in a cage. The heir is mad, they say. No one can reach him...but one woman will try.

Eccentric Harper Forsythe, apprenticed to England's foremost asylum director, has nothing to lose. Only her reputation. Her profession.

Her heart.
But the brother Edward displaced won't allow him to claim his birthright without a fight...

This is a sweeter historical with an HEA and no cliffhangers.