Title: Unknown (2006 film)
Content:  Unknown is a 2006 American mystery thriller film directed by Simon Brand and written by Matthew Waynee. It stars Jim Caviezel, Greg Kinnear, Joe Pantoliano, Barry Pepper, and Jeremy Sisto as a group of men kidnapped and locked in a factory with no memory of how they arrived there. Piecing together information around them, they realize that some were kidnapped and some were the kidnappers. They decide they must work together to figure out how to get away before the gang that captured them returns. The film was previewed before a theater audience for the first time in New York City on December 13, 2005.
Title: Unknown (2011 film)
Content:  Unknown is a 2011 action-thriller film directed by Jaume Collet-Serra and starring Liam Neeson, Diane Kruger, January Jones, Aidan Quinn, Bruno Ganz, and Frank Langella. The film, produced by Joel Silver, Leonard Goldberg and Andrew Rona, is based on the 2003 French novel by Didier Van Cauwelaert published in English as Out of My Head which was adapted as the film's screenplay by Oliver Butcher and Stephen Cornwell. The narrative centers around a professor who wakes up from a four-day long coma and sets out to prove his identity after no one recognizes him, including his own wife, and another man claims to be him. Released on 18 February 2011, the film received mixed reviews from critics and grossed $136 million against its $30 million budget.
Title: The Unknown (1936 film)
Content:  The Unknown (Die Unbekannte) is a 1936 German drama film directed by Frank Wisbar and starring Sybille Schmitz, Jean Galland and Ilse Abel.
Title: The Unknown Purple
Content:  The Unknown Purple is a lost 1923 American silent mystery film that was written and directed by Roland West.
Title: The Unknown (Over the Garden Wall)
Content:  The show, created by Patrick McHale, is based on the 2013 animated short film Tome of the Unknown, which McHale wrote and directed for Cartoon Network Studios as part of their shorts development program. The final episode features Elijah Wood as Wirt, Collin Dean as Greg, Melanie Lynskey as Beatrice, Christopher Lloyd as the Woodsman, and Samuel Ramey as the Beast.
Title: The Unknown Man (2021 film)
Content:  The Unknown Man is an upcoming Australian crime-thriller film directed and written by Thomas M. Wright. The film stars Joel Edgerton, Sean Harris, Steve Mouzakis, Brendan Cooney, Mike Foenander, Alan Dukes, Matthew Sunderland and Jeff Lang.
Title: Tome of the Unknown
Content:  Tome of the Unknown is a short film written and directed by Patrick McHale, who also wrote and storyboarded it. Not long after he graduated from college, McHale pitched the idea for the film, among other concepts, to Cartoon Network. At the time, the network was considering the creation of a department for feature films, though this never came to fruition. McHale was asked if it was possible to adapt the idea for Tome of the Unknown to feature length. This proved unsuccessful as he felt it needed to be episodic, laying out plans for a full television series consisting of three seasons. The project 
Title: Unknown Sender
Content:  UNKNOWN SENDER is an internet television series created in the United States, which debuted in August 2008 on Strike.TV, a website created by Hollywood writers during the 2007–2008 Writers Guild of America strike and later uploaded to YouTube. Like the other Strike.TV offerings which were sanctioned by the Writers' sister union, the Screen Actors Guild (SAG), UNKNOWN SENDER was able to attract major talent to its cast, all of whom agreed to donate profits to the Hollywood charity, Actors' Fund. Among the actors in the series are Timothy Dalton, Joanne Whalley, Mindy Sterling (Austin Powers' "Frau Farbissina"), comedian Jay Davis (Dane Cook's Tourgasm), and Stan Freberg. Behind the camera, noteworthy figures include Academy Award nominee Marilyn Vance and pioneer web filmmaker Kevin Rubio (Troops) among the producers; as well as Lost Director of Photography Edward J. Pei, film composer Adam Cohen (The Incredibles); and Special Effects Supervisor Shant Jordan (Hellboy II).
Title: The Unknown (1915 drama film)
Content:  The Unknown is a 1915 American silent drama film produced by Jesse Lasky and distributed by Paramount Pictures. Directed by George Melford, it stars Lou Tellegen, Theodore Roberts, and Dorothy Davenport.
Title: The Unknown (1915 comedy film)
Content:  The Unknown was a 1915 film directed by J. E. Mathews released in support of The Sunny South or The Whirlwind of Fate (1915). It is considered a lost film.

Question: Who was the screenwriter for Unknown?
Answer: Didier Van Cauwelaert.