Jo Santini walks into the series carrying its heaviest inheritance. Dominic's niece — and a childhood friend of Stringfellow Hawke — she takes over Santini Air after her uncle is murdered in the Season 4 opener, keeping the hangar's lights on while the man who was like family lies broken and the aircraft everyone whispers about needs a new crew.
She is, in the show's own framing, true to her heritage: attractive, fiery and as hard-headed as any problem she comes up against. The trauma of 'Blackjack' would have grounded most people; Jo answers it the Santini way — by flying. Pilot, engineer and the new team's fixed point of loyalty, she is Season 4's clearest link to what the series used to be.
The final season leans on her hard: kidnapped over a dam in 'A Piece of Cake', targeted by a vendetta forty years old in 'Ground Zero', lured to Afghanistan as bait in 'The Golden One', and given the season's most personal hour when her dying father resurfaces in 'Flying Home'. Michele Scarabelli plays it all with an energy the leaner Canadian production badly needed.