Probably not.
Bart is reported to have died in a tavern imbroglio in Portugal. He’d been drinking, he did not understand the language, and he inadvertently insulted a decent woman. Before he realized how much trouble he was in, weapons had come into play.
The very senselessness of his death made his passing harder for his family to grieve. He was the next duke, vivacious, full of himself, dear, and a little hard to take sometimes. He should not have died like that.
Through every book in the eight siblings series, Bart functioned at some level as a specter, a sorrow, a guilt and a grief. I’m hesitant to mess with that, because whatever emotions my characters endure, to some extent, my readers endure them too. My editor’s vote is to leave Bart on the far side of the rainbow bridge.
That said, I do think about the what ifs. What if he staged his death to become a spy, fell in love with the enemy, and had to stage even his spy-death to avoid (unfair) accusations of treason? He’s doubly dead in the eyes of England, and can’t come back to life without a lot of sticky explanations…
I dunno. It could work, or maybe not. What do you think?