The only difference this time around is that Katrina spiked their drinks with whatever was needed to make them feel better. Every other thing she forced her father to take was filled with drugs. It is noteworthy that she would have easily killed Vicker and Sabrina Hastings if she wanted to.
Upon her return, however, Katrina couldn't help wondering if her treatment failed or something. She had been treating Vicker for the past six years, without his knowledge. Katrina didn't want her dad to be all jittery and become too anxious for a cure, or for him to be too pessimistic about his own recovery.
As a result, she chose to do everything on the blind side of the couple. Her two other sisters also knew she was treating their parents, as they also contributed to Vicker consuming various drugs without knowing.
