Ronan and Maeve Fitzpatrick, and Niall Horan pledged to be best friends until they were 104. But promises can be hard to keep when your twin brother dies from leukemia whilst your friend is away on the X Factor. After two years without contact, they find themselves stuck together again, and they both begin to receive mysterious letters from somebody claiming to be Ronan. Will Maeve and Ronan be able to forgive and forget? Or will the two find it impossible to ever find common ground?