The team investigates the death of a woman in rehab.
Tropes:
- Accidental Murder: Ken never meant to kill Daycia, he just wanted her to shut up but held her under a pillow too long.
- Hard-Drinking Party Girl: Daycia was the embodiment of it, and even in rehab she still snuck out to go drinking. A nurse comments she thinks Daycia would never recover.
- Make It Look Like an Accident: When Ken realized he killed Daycia, he saw her tub was filled with water and so pumped water into her lungs to make it look like she just drowned.
- Rage Breaking Point: This was Ken's motive: he was tired of Daycia being a little devil and tempting the other patients into their old patients. After she left a bottle of his favorite brand of alcohol at his bed, he finally snapped.
- Spanner in the Works: Ken wanted to make it look like Daycia drowned in her bath, but then Adam disposed of the body somewhere else, and the circumstances led the CSI team to him.
- Sympathetic Murderer: Ken is a recovering addict who is taking his treatment seriously for the sake of being allowed to see his children again. Daycia had a rich husband and little to lose if she failed the course and enjoyed goading others into giving in to their vices. She put a gift-wrapped bottle of bourbon in Ken 's room and kept pushing him to drink it until he snapped and killed her by accident. To really push it even after all that, Ken still never drank a drop and breaks down crying in the station when he realises that he'll never see his sons again.
- Tragic Villain: Ken. All he wanted was to be able to sober up so he wouldn't lose custody of his kids, but now he'll probably never see them again due to his crimes. He tearfully says in his confession he never drank once: he just dumped the bourbon in the toilet.
