mysterious

mystical

investigation

background

investigative

forensic

forensic investigation

spy

spies

secret

secrets

secret agent

under cover

undercover

police work

detective

private detective

clues

information

suspect

suspicion

criminal

criminal investigation

danger

dangerous

secret mission

intense

texture

impending doom

emotional struggle

anticipation

action

human interest

news cue

pollution

growing problem

problematic

complex

cool

cold

tension

tense

anxious

complicated

dissonance

evil

tricky

taxing

difficult

vexed

clue

impend doom

grow problem

tax

vex