Time travel is a tricky endeavor. You must familiarize yourself with the many rules and paradoxes your story’s world subscribes to. Before incorporating it into your writing.
For this discussion, I’ll use the season four premiere of “Sanctuary.” Namely, things that apply the Butterfly of Doom concept. I won’t go into much detail about the episode’s plot itself, but for those who haven’t yet caught up: Spoilers Ahead!
Helen Magnus and a group of her closest companions were each gifted with special abilities. Among them is longevity of life. So, while they’re originally from 19th-century London, they’re alive and well in the 21st century. At the end of season three, Magnus follows the seasonal arc’s antagonist through a time portal. This lands the 160-year-old doctor back in 19th-century London. Cue the dramatic music, and the end of the season.
At the start of season four, Magnus must save her original time line from being changed forever. Which means successfully stopping the antagonist’s evil-genius plan. And avoiding any and all contact with 19-century folk that will “compromise history as we know it.”
Constant Battle With Time Travel
But, hang on… Magnus and the antagonist have already disrupted history as we know it. They returned to the past! And this is where I have major issues with time travel.
Our Magnus makes contact with an old friend. She’s reminded how vital it is not to bump into anyone, nor reveal any knowledge she has of the “past”–once more her present.
And yet the mere act of travelling back in time is enough to alter history. Even if done with the full intent of not “getting caught.” Theoretically, if a character is successful in avoiding contact with anyone s/he knows, nothing changes. The character wins, history remains the same.
But we must also consider the minor people and events in history as we know it. These are the tiny ripples that stories often overlook in regards to time travel.
The Ripple Effect
I once answered a writing prompt about strangers who pass through our lives. The prompt’s focus was the impact that small encounters have on the rest of our lives. My piece twisted this around. My speaker was the stranger passing through the lives of others.
It was based off a lesson from my job at a small-town amusement park. A story from a family who wrote in about their last experience at the park. Basically, the family came and had a fun day with their aunt, a woman they didn’t often get to see. Upon leaving, a park employee offered to capture a photo of the family, so they could have a group shot of them with their aunt.
The letter was a grateful thank you. The family learnt shortly thereafter that their aunt had cancer, and consequently died. The photo is the last one they have together.
A small, simple action that caused a major life change.
The Bigger Picture
My point, going back to time travel, is that even though characters believe they’re staying in the shadows, they don’t consider the effects of their adventure through time. They avoid any major ripples in their own lives, and those of the people they know. Not the smaller, potentially more dangerous ripples.
Suppose your character’s lingering presence in the shadows deters a killer from using that route to track his next victim. The victim lives, thereby creating a new history where the victim’s existence in turn changes the lives of everyone now connected by someone with whom they never would have met if the past hadn’t been tampered with.
Magnus starts her journey lying in rubble in the streets. People stop to see if she’s all right, delaying wherever it is to which they travel. Someone might be late for an interview, thereby losing a job they originally won, etc.
The ripples are never-ending, and ever-widening. Whoops.
Co-Existing Time Travel Theories
Some may bring to light the possibility of parallel universes. It’s a popular theory that going back in time doesn’t affect current events, but instead creates an alternative timeline. In this case, though, there’s no reason to go back in time to stop the villain from messing things up, because the alternate won’t impact the current strand of time.
We would then debate our place in “saving” that alternate line. Furthermore, we’d have to consider whether or not we could return to our timeline as we know it after the time travel.