A Step into the Past is a 2001 Hong Kong television series produced by TVB and based on Huang Yi's novel of the same Chinese title.

The series tells the story of a 21st-century Hong Kong VIPPU Inspector who travels back in time to the Warring States period of ancient China.

Moments later, wealthy businessman Lee Siu-chiu is attacked and held hostage at the museum by a madman who had suffered losses in the stock market.

Impressed with Hong's rescue attempt, Lee Siu-chiu and Doctor Wu Yau recruit him for a secret time-travelling experiment.

He is tasked to travel back more than two thousand years to the Qin dynasty, half an hour prior to the coronation of Ying Ching in 247 BC, and document the event with a digital camera before a swift departure.

In order to return to the future, Hong has to make an arduous journey across thousands of miles in ancient China to activate a device at a specific location and time.

He was warned that making even a slight change in the grand scheme of events will trigger a chain reaction of catastrophes that will alter history.

His knowledge of the 21st century, intelligence and experience as an elite special agent, as well as his prowess in martial arts, enables him to make a strong stand in history.

Raymond Lam, in his first major role, was highly praised for his breakthrough performance as Ying Ching, and rose to fame quickly.

After its 2005 midnight re-run, TVB decided to release the complete series on DVD and VCD for the first time on November 18 in the same year.

[2] In March 2018, One Cool Film Productions (天下一電影製作有限公司) confirmed that it has cast Lam and Hsuan to reprise their roles as Ying Ching and Wu Ting-fong, respectively.

[3] A year later in March 2019, Back to the Past held its first press conference, also announcing that Kwok, Tang, and Saram will be returning, though it was not specified if they will be reprising their original roles.