Queen of Hearts
“...the Queen of Swords finds an unlikely comrade in Robert Helm (played by Peter Wingfield), an English Doctor who trades his musket for a scalpel, vowing to save lives, not take them.
He has little patience for Tessa, believing her to be a spoiled member of the nobility, and less for the Queen of Swords, despising the blades with which she deals justice, yet Helm keeps finding himself strangely attracted to the beautiful avenger in black.”
— from Queen of Swords Presskit
“Methos (played by Peter Wingfield) is an Immortal and a friend of Duncan MacLeod. Reputed to be the oldest living immortal, he has met many historical figures over the years, and has been a few as well.
In one of his early incarnations became a legend, known as Death of the Four Horsemen. He has assumed countless aliases over the centuries, one of his most recent known was that of Adam Pierson, a (former) Watcher researcher.”
— from Highlander Wiki