|17-year-old Marty McFly lives with a grim and bleak family in Hill Valley, California. His father, George, is constantly bullied by his supervisor Biff Tannen, and his slobbish overweight mother, Lorraine, has a drinking problem. Marty's girlfriend, Jennifer Parker, encourages him to pursue the dream of being a rock musician.
|On October 26, 1985, Marty's friend and eccentric scientist Doc Brown shows him a DeLorean which he has modified into a time machine powered by plutonium. However, before Doc can make a trip into the future, the Libyan terrorists he stole the plutonium from show up and gun him down. Marty attempts to escape in the DeLorean but is accidentally transported back to November 5, 1955.
|In 1955, Marty runs into his teenage father George, who is being bullied by Biff. As George is about to be hit by Lorraine's father's car, Marty pushes him out of the way and takes the impact. As a result, Lorraine becomes infatuated with Marty instead of George. To make matters worse, Marty did not bring back any additional plutonium to power the time machine, so he must find the 1955 version of Doc Brown to help him return to 1985. Doc tells Marty that the only possible source of that amount of power is a bolt of lightning. He also deduces that Marty has prevented his parents from meeting. He tells Marty he must find a way to get them together or he will never exist.
|Marty plans to have George appear to rescue Lorraine from Marty's overt sexual advances on the night of the school dance. However, a drunk Biff unexpectedly shows up and forces himself on Lorraine. George arrives as planned to rescue Lorraine from Marty but finds Biff instead. Biff subjugates George, but George punches Biff in the face, knocking him out. A smitten Lorraine follows George to the dance floor, where they kiss for the first time, assuring Marty's existence.
||在校园舞会之夜，马蒂计划假装调戏洛莲，让乔治到时跳出来英雄救美。然而出人意料的是，喝的醉醺醺的毕夫突然出现并开始骚扰洛莲。乔治按照计划前来救美，结果发现他的对手从马蒂换成了毕夫。毕夫威胁乔治，但乔治给了他迎面一拳，将他击昏在地。乔治的勇敢打动了洛莲，两人步入舞池，第一次亲吻对方 —— 这一标志性事件确保了马蒂能够继续存在。
|Meanwhile, Marty writes Doc a letter to warn him of his murder in 1985. The lightning strike at 10:04 pm successfully sends Marty back to 1985, but he is too late to prevent Doc from being shot. However, Doc reveals he was wearing a bulletproof vest after reading the letter.
|When Marty returns home, he finds that his family situation has improved because of the way his parents' relationship was changed by his intervention in the past. Lorraine is physically fit, and George has become a self-confident and successful science fiction author. Biff has become an auto-detailer, and is now very deferential toward George. Just as Marty reunites with Jennifer, Doc arrives, insisting that they accompany him to the future to sort out his children.
（China.org.cn Rebecca 译）