...They investigate the singer's many fans and foes in the music circuit, and, in particular, one obsessed woman who redirects her affections toward Booth after Tommy's death...
NOTHING, it's been suggested, kills a TV show quicker than requited love. History is littered with the remains of shows that fizzled and died when the old "will they or won't they" sexual chemistry was resolved.
Suspension of disbelief" is the willingness to acept non realistic elements in a tale if the author infuses a semblance of truth or a human interest. During Booth's illness, Brennan willingly believes her own stories.