We haven’t yet mapped out the time travel itinerary.
INDEXER NOTES (SPOILERS!)
Credits—There’s no writer credited in the film, although <a href='https%3A%2F%2Fwww.imdb.com%2Ftitle%2Ftt4608638%2Ffullcredits'>IMDb</a> credits Christopher Ashton, so we’ve listed him as the uncredited writer.