have revolutionaries topple the government and machine-gun the entire wedding party. Other primetime soap operas, such as Falcon Crest and Knots Landing, also employed dramatic end-of-season cliffhangers on an annual basis. Sitcoms also utilised the cliffhanger device. As well as the aforementioned Soap, the long-running sitcom Cheers would often incorporate cliffhanger season endings, largely (in its earlier years) to increase interest in the on-and-off relationship between its two lead characters, Sam Malone and Diane Chambers. These cliffhangers did not place the characters in peril of any kind, but rather left their relationship (which was at the core of the show) hanging in the balance. Cliffhanger endings in films date back to the early 20th century, and were prominently used in the serial films of the 1930s (such as Flash Gordon and Buck Rogers), though these tended to be resolved with the next installment the following week. A longer term cliffhanger was employed in the Star Wars film series, in The Empire Strikes Back (1980) in which Darth Vader made a shock revelation to Luke Skywalker, and Han Solo's life was left in jeopardy after he was frozen and taken away by a bounty hunter. These plotlines were left unresolved until the next film in the series, which was released three years later. The first two films in the Back to the Future series end in cliffhangers, with the first displaying the "to be continued" title card. The two main ways for cliffhangers to keep readers/viewers coming back is to either involve characters in a suspenseful, possibly life-threatening situation, or to feature a sudden shocking revelation. Cliffhangers are also used to leave open the possibility of a character being killed off due to the actor not continuing to play the role. Cliffhangers are also sometimes deliberately inserted by writers who are uncertain whether a new series or season will be commissioned, in the hope that viewers will demand to know how the situation is resolved. Such was the case with the second season of Twin Peaks, which ended in a cliffhanger similar to the first season with a high degree of uncertainty about the fate of the protagonist, but the cliffhanger could not save the show from being canceled, resulting in the unresolved ending. The final episodes of soaps Dallas and Dynasty also ended in similar fashion, though all three shows would return years later in some form or other to