10 Times Scotty Saved The Day In Star Trek
5. Nuclear Charging Dilithium Crystals
In the fourth Star Trek film, the story sees Kirk, a newly resurrected Spock and the rest of the crew returning to Earth via an old, captured Klingon Bird of Prey. However, a probe of unknown origin appears in the skies above Earth, beginning to vaporise the planet's oceans. Spock deduces the message it broadcasts is meant for Humpback Whales, which are extinct in their time, so the ship travels back in time.
There is however a rather large snag on the other side. Once through, Scotty informs the Admiral that the trip has burned out the dilithium crystals powering the ship's warp drive. Without it, they will soon be unable to escape back to their own time.
With the aid of Spock, Scotty is able to use the power generated from nuclear fission to re-crystalize their supply. It is a dangerous mission (one that results in the capture and rescue of Chekov) but it is ultimately a success. Scotty is able to fire up the engines and get them back to the 23rd century. All of this, and after having contructed a whale tank to boot!