Isobel Gabriel leaves a letter for her son, Tom, to be read one month after her death. Her revelations take Tom back in time and throw into turmoil his settled life as a committed and respected GP. Isobel's long-held secret affects Tom's strained relationship with his uncommunicative sister, Sarah and brings a new understanding of his cold and homophobic, late father, Edward. Discovering more about the woman he had only ever known as his mother, compels Tom to embark upon a quest. Supported by his partner, Alex and with unforeseen hurdles to overcome, Tom goes in search of the missing pieces...