In love, engaged, married. The big love. Forever. That's how it starts. But why does it usually end differently? That the most beautiful feeling in the world, this music in the heart, so often fades away and is forgotten? Marianne and Günter, married for over 50 years, don't know. The children are out of the house, what remains is a joyless routine and a certain resignation. And then there's the matter of their memory: lately they seem to be getting increasingly forgetful. Just as Günter seems to have forgotten their wedding anniversary today. But he hasn't at all: from a friend he has procured a brand new pill that is supposed to bring back all memories in record time. The miracle happens: suddenly everything is back. Together they travel back in time, to the highs and lows of their lives, until they finally remember the most important thing: what they fell in love with. And so they fall in love again - feeling young again, it's like a rush, they make plans - nothing can stop them. But what if the effect of the pill wears off again...?