Sailor's Jewel
Set in November 1901, during The Moonstone's crossing of the Atlantic, Cyrus Smythe-Clive and Rhoe Belisama (brother and sister) have some unexpected adventures.
Cyrus is fulfilling a task from the The Council, while Rhoe is taking a brief holiday before taking up new duties at the Temple of Healing. When Rhoe meets Hugh Pelagius, and they have to work together with Nerissa to deal with a threat from beneath the waves, it's clear it's no ordinary voyage.
Hugh Pelagius (main)
Cyrus Smythe-Clive (secondary)
Also: Nerissa (one of Merope's Speakers), various passengers and staff of The Moonstone
Content notes for Sailor's Jewel (click to read)
Main character is a healer: discussion of her work (without extensive medical detail) throughout. A secondary character is a widower whose much-loved wife died in childbirth. Nasty gossip and references to bigotry about characters who are not entirely human, or do not fit neatly into societal expectations.
Notable people
Rhoe Belisama (main)Hugh Pelagius (main)
Cyrus Smythe-Clive (secondary)
Also: Nerissa (one of Merope's Speakers), various passengers and staff of The Moonstone
Related books
Rhoe also appears in Carry On, and Cyrus Smythe-Clive is in a number of other books, most notably Old As The Hills and Upon A Summer's Day.