Beverly and the Enterprise travel to Caldos IV to attend the funeral of her grandmother, Felisa Howard. While spending the night in Felisa's house, Beverly hears a man's voice. He identifies himself as Ronin, a ghost that has loved the women in Beverly's family for eight hundred years. When Beverly falls under Ronin's spell, she abruptly resigns her post on the Enterprise to remain on Caldos.

Duncan Regehr (Ronin)
Shay Duffin (Ned Quint)
Michael Keenan (Governor Maturin)
Ellen Albertini Dow (Felisa Howard)

• Sub rosa is Latin for "in secret."
  
• The Caldos Colony was one of the Federation's first terraforming projects, created nearly a century ago. The cornerstone of every building was brought from Edinburgh, Glasgow or Aberdeen in Scotland.
  
• Beverly discovers Ronin is not a ghost, but an anaphasic lifeform that has been using the women in her family to stay alive.
  
• After Quint is killed by Ronin, Beverly has his body sent to the ship for Dr. Selar to examine.
  
• Duncan Regehr also plays Bajoran First Minister Shakaar Edon on Deep Space Nine.
  
• Michael Keenan also played Hrothgar in the Voyager episode "Heroes and Demons" and Patrick in the DS9 episode "Statistical Probabilities".
  
• This episode is a gothic ghost story and isn't very popular amongst fans. (I find it campy and fun, though. And it's certainly not the worst episode of the series.)