4When Ava's partner Will is diagnosed with a terminal brain tumour, the doctors give Will one chance to survive - an operation which means he will lose his recent memory. Ava begs him to take the chance, sure that she can cope with Will forgetting her. After all, they have something very special to live for. But they are also keeping a heart-breaking secret, and if Will loses his memory, Ava will have to carry that secret alone. Can they rebuild their love from scratch or will their secrets and past come between them? Will Ava really be a stranger when Will wakes up - or does the heart never really forget...