Choi San-keung, a taxi driver who perpetually lacks sleep, thus endangering anyone who sets foot in his taxi. One passenger is psychiatrist Dr Man, who survives the taxi ride and offers to help Choi. The offer is refused, but Choi later becomes Dr Man`s involuntary patient after a particularly egregious night of driving. Dr Man has his own personal issues: his motto is "I think a doctor should do more than prescribe meds," which means a doctor should also investigate his patients secretly in defiance of common sense and hospital protocol. In a parallel to Choi, Dr Man also has sleeping issues. He suffers from disturbing dreams of his deceased mother, which hints at a secret involving his father, and perhaps some repressed memories.