Identical twins, Sinéad and Sheila Fields, have always done everything together and so, after graduating in millinery, they decide to open their own hat shop. It's a small business but thanks to hard work and talent, they build up a loyal clientele. Then one day a glamorous young actress buys one of their hats, wears it to the Baftas and suddenly success seems guaranteed.
But within weeks, tragedy strikes when Sheila disappears, and is presumed dead. After months of desolation, Sinéad is just beginning to come to terms with her loss when she is given new hope: there has been a sighting of her sister. While she is filled with excitement at the thought that Sheila might be alive, she is haunted by questions. Why would Sheila have deserted her twin without a word? After all, they had always told each other everything … hadn't they?