The film centers around a writer, Alan Tam (Anthony Wong), who has spent the last decade in a mental hospital. Upon leaving, he rents an apartment in an abandoned building which contains a clock that sends him back to 1984. The only person that can hear Alan during this time is one of the previous tenants, a young girl named Dolphin (Dolphin Chan). A strange romance soon develops between the two, and so when her sister Whale (Perrie Lai) begins dating a suspicious professor (Lawrence Ng), Alan helps Dolphin to find out the shocking truth about her sister's beau.