The film follows Joel Barish (Jim Carrey), a reserved introvert who discovers that his ex-girlfriend, the impulsive Clementine Kruczynski (Kate Winslet), has undergone a procedural memory erasure to delete all traces of their relationship. Out of spite and heartbreak, Joel seeks the same treatment from Lacuna, Inc..

Because a mind with memories—messy, painful, beautiful memories—is not a prison. It is a lighthouse. And even when the light flickers, it guides you home.