Murder Mystery plot option
Char gets sucked into entourage of rock star. Contacts sister to plead for help as entourage are being picked off 1 by 1. Disappears. Killer strangles victims with feather boa. Many ppl have motives – jealousy, money, homophobia. Turns out the entourage are aliens being killed by other aliens in a mafia stylee, OR being removed by the authorities who have found them out… might be best is we never find out if they are actually aliens or not, just have the killer believe they really are. Leave the reader uncertain. Are they/aren’t they, are they/aren’t they? Hehehe.
Have another undercover agent working for the government… have people change, or appear to change, loyalties.