Jennifer Aniston personifies seemingly insurmountable emotional and physical pain in Cake. She does such a great job of looking and sounding miserable, it wouldn't be surprising to hear crew hands were driving nails into her feet out of the camera's view during takes. The reasons for Claire's misery are not made clear until well into the film, a wise choice by director Daniel Barnz and screenwriter Patrick Tobin. Not only does it provide the film with a decent mystery, it allows the focus to solely be on Claire in the moment, struggling from second to second with physical back pain and some sort of loss. Aniston somehow manages to make Claire a sympathetic character despite her constant unpleasantness. While we only get glimpses of the Claire that might've existed before her back and heart became racked with pain, it's obvious that Claire was somebody that many people cared for. She's pushed them away for what is revealed to be solid reasons. The pain of her losses never leaves Aniston's face, even in the moments when she is smiling. The supporting cast includes Sam Worthington, Adriana Barraza, Anna Kendrick and Felicity Huffman, and they all shine. This is a triumph for Aniston, who delivers a career best performance.