Ethan is still in hot pursuit of Dani. He even asks her to the movies to see Prom Zombies 4. Dani politely declines his offer and it's not because she hasn't seen Prom Zombies 1, 2 or 3. She has a date with Peter, who becomes the target of Ethan's ire simply because he's dating the woman he desires. Curtis is also upset due to his new diet. But the real issue is the notion that he doesn't always believe he's good enough.
Even after she had found love with her ex, Zack, Melissa was never happy with how she looked. Melissa's relationship with her dad became strained after she started getting cosmetic surgeries. Megan isn't thrilled with the plastic surgeon, Dr. Sarah Hughes, who kept operating on a vulnerable young girl. But Zack Goffman becomes a prime suspect when the team learns that he's the one who paid for all of Melissa's surgeries.
Megan believes Melissa's maid of honor also deserves consideration suspect wise. She's a nurse who gave the bride-to-be some aspirin even though she knew it would give her a black eye when combined with botox injections. The maid of honor was ticked because Melissa stole Marc from her, but she didn't kill her. Zack jumps to the front of the suspect line again when video footage shows him at the hotel on the wedding day.