Heroes in stories overcome seemingly impossible odds. Time and again they're saved by some minor detail - one person in the right place at the right time, a switch at the last minute, a choice to go left instead of right, an item picked up on a whim. Often, it's a series of minor details, seemingly unrelated, one after another. Tolkien described this in The Two Towers as "the falling of small stones that starts an avalanche in the mountains."
Consider the number of "lucky breaks" early in the recent Star Trek reboot. The Narada dispatches all of the Starfleet ships that engage it. Only the Enterprise survives because it arrived late and with foreknowledge of the attack.
- Kirk overhears Uhura's translation of a Klingon transmission, then
- Uhura convinces Spock to change her assignment from the Farragut to the Enterprise, and
- Bones helps Kirk fake an illness to be brought on-board as a patient, so that
- Kirk is on the Enterprise to hear the description of a "lightning storm in space" which, coupled with the Klingon transmission, fits the story of an attack when he was born.
- Uhura is on-board to confirm his story, leading Captain Pike to order the shields up and battle stations, which they have time to do because
- Sulu forgot to turn off the "parking brake".
Another worldview sees providence. Call it fate, call it luck, call it karma. I believe everything happens for a reason.* Rather than arguing that this story can be told because those events unfolded, this view holds that those events unfolded so that the story can be told. This view sees authorship, and I would call that author not fate or karma but God.
The funny thing about this particular sequence of events is that it did have authors - Orci, Kurtzman, and, indirectly, Roddenberry. One of these worldviews is clearly correct, as this sequence was scripted, acted, and carefully edited to be just what it is.
What about your story? And the world's?
* As does Dr. Venkman. Bonus points if you recognized this reference to Ghostbusters. And, no, I don't believe in fate, luck, or karma; but I've had a burning desire to squeeze in a Ghostbusters quote.