The Blackheath Poisonings (1993)

S1E2 Episode 2

In the wake of Roger's demise, Harriet decides to bring in Robert, Charlotte's former love, to take his place. Simultaneously, Isabel finds herself being blackmailed, which piques the interest of the eccentric Inspector Titmarsh. Paul sees this as an opportunity, hoping the inspector can assist him in uncovering the truth behind his father's death.