繪畫香港一些即將消逝的事物，有一幢幢如小型社區的唐樓、已被清拆的喜帖街、天星碼頭、伴隨所有香港人長大的電車、有香港特色的舊食肆，香港的傳統節日等等。

Leonard Shelby is tracking down the man who raped and murdered his wife. The difficulty of locating his wife's killer, however, is compounded by the fact that he suffers from a rare, untreatable form of short-term memory loss. Although he can recall details of life before his accident, Leonard cannot remember what happened fifteen minutes ago, where he's going, or why.

Joel Barish, heartbroken that his girlfriend underwent a procedure to erase him from her memory, decides to do the same. However, as he watches his memories of her fade away, he realises that he still loves her, and may be too late to correct his mistake.