In suspense novels even subplots about relationships have to have conflict.
In the shaded portions where the two spheres of different lives meet, certain fundamentals- moods, loves, fears, angers- can't be hidden. That's the contract.
Ideally, I like to integrate the human issues into the suspense story itself.
For me a thriller is a very carefully structured story.
Certainly going back to Sherlock Holmes we have a tradition of forensic science featured in detective stories.
Six Seconds is a great read. Echoing Ludlum and Forsythe, author Mofina has penned a big, solid international thriller that grabs your gut -- and your heart -- in the opening scenes and never lets go.