Lisa (Nina Hoss), once a brilliant and renowned playwright, has lost her creative spark. She lives in Switzerland with her family, but her heart remains in Berlin, beating in time with that of her twin brother Sven (Lars Eidinger), a famous theatre actor. The ties between the twins have grown stronger since Sven was diagnosed with an aggressive type of leukaemia. Lisa refuses to accept his fate and does everything in her power to get him back on stage. She gives her all for her soul mate, neglecting everything else, even risking her marriage. Her relationship with her husband starts to fall apart, but Lisa only has eyes for her brother, her mirror, who connects her back with her deepest aspirations and rekindles her desire to create, to feel alive again.