Chuck Versus the Cliffhanger

"Chuck Versus the Cliffhanger" is the fourth season finale of the American NBC action-comedy television series Chuck. Aired on May 16, 2011, it is the season's 24th episode, and the 78th overall episode of the series. The episode was directed by Robert Duncan McNeill and written by series co-creator Chris Fedak, along with Nicholas Wootton. Despite the episode's eponymous cliffhanger ending, supposedly leading into a fifth season, it was anticipated that Chuck would be cancelled after the fourth season for declining viewership, making "Chuck Versus the Cliffhanger" the de facto series finale. However, a fifth and final season was ordered on May 13, 2011.

Chuck revolves around the Intersect, a government database designed by Stephen J. Bartowski. In the pilot episode of the series, Stephen's son Chuck (Zachary Levi) receives the database and accidentally uploads it to his brain. Chuck is then forced from his life as an employee at the big-box store Buy More to the spy world. By the fourth season, Chuck is a Central Intelligence Agency (CIA) agent and is engaged to one of his handlers, Sarah Walker (Yvonne Strahovski).

In the season, Chuck and his team fulfill Stephen Bartowski's last wish to destroy Volkoff Industries, led by international arms dealer Alexei Volkoff (Timothy Dalton). It is then revealed that Volkoff was actually Hartley Winterbottom, an MI6 scientist who worked with Stephen in the 1980s. In preparation for an undercover assignment as an arms dealer named Alexei Volkoff, Winterbottom became the first person to upload the Intersect. However, the upload malfunctioned, overwriting Winterbottom's personality with that of his cover, and Stephen spent the last 20 years of his life trying to fix his mistake. At the end of "Chuck Versus the Last Details", Volkoff's daughter Vivian (Lauren Cohan) learns of her father's true identity, and, holding Chuck responsible, poisons Chuck's fiancée Sarah with a Volkoff Industries weapon called "the Norseman". To save Sarah's life and stop Vivian from destroying his and Sarah's wedding, Chuck turns to Alexei for help. To keep secret Volkoff's true identity, the CIA sends its "toughest" agent, Clyde Decker (Richard Burgi), to stop Chuck.

"Chuck Versus the Cliffhanger" received overwhelmingly positive reviews from critics. According to the Nielsen ratings system, it drew 4.53 million viewers, with a 1.5/4 rating among those aged 18–49.