Back to the Future follows the adventures of Marty McFly, who discovers a Delorean that has been modified to time travel when it reaches a speed of 88 miles per hour. Marty travels back in time to 1955 from 1985 accidentally while escaping a terrorist, and tries to find plutonium to replenish power to the time circuits, which as it turns out, plutonium happens to be scarce in 1955. He ends up staying in 1955 for a while, and eventually figures out a way to travel back to 1985: by having a lightning rod attached to the car and have lightning strike it as he approaches a wire at 88 miles per hour