A line like 'only time will tell' can feel like a playful dodge or a deliberate breadcrumb. When an author drops that phrase in dialogue or narration, my gut flips between two readings: either it's a sincere shrug—time literally reveals what happens—or it's a wink, a way to nudge the reader to pay attention to temporal patterns, repeated motifs, or the way the story withholds information. In novels with long foreshadowing arcs, similar refrains often point to a planned payoff; in thrillers it can signal that a reveal is coming in a future installment.
That said, not every invocation carries authorial omniscience. Publishing schedules, serial formats, and character uncertainty can all produce the same line without meaning the writer already fixed an ending. I like to cross-check: does the line align with structural clues like thematic repetition, Chekhov's guns, or a narrator who hints at knowing outcomes? If those are present, 'only time will tell' starts to feel like an intentional hint. If not, it's probably atmosphere or philosophical tone. Either way, it makes me read more closely and savor the slow-building suspense — I love that itch it creates.