About Time costars Margot Robbie and Domhnall Gleeson have reunited for a movie that will surely make us all weep buckets. Goodbye Christopher Robin tells the story of how British author A.A. Milne (Gleeson) found the inspiration for Winnie-the-Pooh and The House at Pooh Corner in the 1920s while raising his son, Christopher Robin. Robbie plays Daphne Milne, and Kelly Macdonald also appears as Olive, Christopher's nanny. Grab a tissue or two and check out the trailer above, before the movie arrives in theaters on Oct. 13.