When Emma finds an old letter in a library book she is instantly intrigued, but through her research into the origin of the letter she unwittingly opens the door to danger. As her life starts to unravel around her, she takes steps to protect herself, but the risk is not always where she would expect to find it. An innocent excursion turns into a nightmare, and she is forced to take a calculated risk to get away. Walking along a lonely road on a winter evening, soaking wet and shivering with cold, Emma is forced to reconsider how long she can last without help and takes a leap of blind faith into the unknown.