Disclaimer: Don't own In Plain Sight, belongs to... whoever it is that does, I dunno who.
Mary would be the first to tell people she wasn't religious. She'd never really forgive what happened just after her dad left. Didn't mean she didn't believe there was something there, watching over her and her witnesses.
She'd never lost a witness, not really. Those that got themselves thrown in jail weren't her concern, and those that died completely out of left field were sad and unavoidable, but never had an assassin so much as seriously frayed her charges hair.
Marshall could, and probably would, laugh if she admitted it out loud after all the times she'd mocked his talks about how in culture a they believed this and in culture b this, but Marshall Mary Shannon knew it wasn't some massive amount of skill, luck, determination (though that was also present in large quantities), nor any quality she possessed that kept her record spotless. Every time one of her witnesses, or her partner for that matter, was in true danger a deadly calm would sweep over her then a whisper, a thought, or a feeling and suddenly she'd know what to do. Never did it fail.
If Mary had been a different kind of person she might have noticed the spectral knight standing behind her. Ever vigilant and watchful over one of his chosen. A spirit of protection.