Seamus Patrick Dever (born July 27, 1976) is an American actor.

Dever was born in Flint, Michigan, and grew up in Bullhead City, Arizona. He graduated as valedictorian of his high school class, completed his undergraduate studies at Northern Arizona University, and holds MFAs in Acting from the Moscow Art Theatre and Carnegie-Mellon University.

A lifetime member of The Actor's Studio, Dever married Juliana Dever May 27, 2006. Juliana plays Jenny, Ryan's wife, in Castle. He is a cousin of Broadway actress Jeanne Arnold and Canadian singer-songwriter (Leslie) Feist.

Dever is best known for his portrayal of Detective Kevin Ryan in the ABC series Castle.

Jon Huertas, born Jon William "Scott" Hofstedt and sometimes credited as John Huertas, is an American actor. He is best known for his role as Sergeant Antonio 'Poke' Espera in HBO's Generation Kill, Joe Negroni in the film Why Do Fools Fall in Love, and homicide detective Javier Esposito in Castle.

Huertas's career started in 1993 when he played an uncredited part in the The Webbers.

In 1998, Huertas portrayed Joe Negroni in the romantic drama Why Do Fools Fall in Love alongside such stars as Halle Berry, Paul Mazursky, and Ben Vereen. In 1999, he appeared in two films: the horror movie Cold Hearts and the action movie Stealth Fighter. In the 2000s, he appeared in many films, but his biggest role was in television in 2008 as Sergeant Espera in HBO's miniseries Generation Kill about the 2003 invasion of Iraq.

In 1998-1999, Huertas played the part of Antonio in the television series Moesha. In 1999-2000, he played Brad, a witch hunter, in Sabrina the Teenage Witch.

Beginning in 2009, Huertas has starred in the role of Detective Esposito in ABC's police procedural Castle.

Stevland Hardaway Morris (born May 13, 1950 as Stevland Hardaway Judkins), known by his stage name Stevie Wonder, is an American singer, songwriter, and multi-instrumentalist, a child prodigy who developed into one of the most creative musical figures of the late 20th century. Blind since shortly after birth, Wonder signed with Motown's Tamla label at the age of eleven, and continues to perform and record for Motown to this day.

Among Wonder's best known works are singles such as "Superstition", "Sir Duke", "I Wish" and "I Just Called to Say I Love You". Well known albums also include Talking Book, Innervisions and Songs in the Key of Life. He has recorded more than thirty U.S. top ten hits and received twenty-two Grammy Awards, the most ever awarded to a male solo artist. Wonder is also noted for his work as an activist for political causes, including his 1980 campaign to make Martin Luther King, Jr.'s birthday a holiday in the United States. In 2009, Wonder was named a United Nations Messenger of Peace. In 2008, Billboard magazine released a list of the Hot 100 All-Time Top Artists to celebrate the US singles chart's fiftieth anniversary, with Wonder at number five.

Stana Katic (English pronunciation: /ˈstɑːnə ˈkætɨk/; born April 26, 1978) is a Canadian film and television actress. She is best known for her portrayal of Detective Kate Beckett on ABC's Castle.

Katic was born in Hamilton, Ontario, Canada, to a Serbian father and Croatian mother, who both immigrated from Yugoslavia. Her father is from Vrlika, and her mother is from the surrounding area of Sinj. Katic later moved with her family to Aurora, Illinois. She spent the following years moving back and forth between Canada and the United States. After graduating from West Aurora High School in 1996, she studied acting at Chicago's Goodman School of Drama. She has four brothers and one sister.

Katic played the character of Hana Gitelman in Heroes, Collette Stenger in 24 's season 5, and Jenny in the film Feast of Love starring Morgan Freeman. She also played Morgenstern in Frank Miller's film The Spirit, Corrine Veneau in the Bond movie Quantum of Solace (though she was originally up for the role of Strawberry Fields in the film), and Simone Renoir in the third installment of The Librarian franchise, The Librarian: Curse of the Judas Chalice.

Nathan Fillion (pronounced /ˈfɪljən/, as in million; born March 27, 1971) is a Canadian actor, currently starring as Richard Castle on the ABC series Castle. He is also known for his portrayal of the lead role of Captain Malcolm Reynolds in the television series Firefly and its feature film continuation, Serenity.

He has acted in traditionally distributed films like Slither and Trucker, Internet-distributed films like Dr. Horrible's Sing-Along Blog, voice-over work like the video games Halo 3: ODST and Halo: Reach, television soap operas and sitcoms, and in the theatre.

Fillion was born in Edmonton, Alberta, the younger son of Cookie and Bob Fillion, both of whom are retired English teachers. He has an older brother, Jeff, and attended Holy Trinity Catholic High School, Concordia University College of Alberta, and the University of Alberta, where he was a member of the Kappa Alpha Society. According to Fillion, he is descended from Confederate Lieutenant General Jubal Anderson Early.

After working in several theatre, television and film productions, including Theatresports with Rapid Fire Theatre and the improvised soap opera Die-Nasty, Fillion moved to New York City in 1994 where he acted in the soap opera One Life to Live as Joey Buchanan, for which he was nominated in 1996 for a Daytime Emmy Award for Outstanding Younger Actor in a Drama Series. In 1997, he left the series to pursue other projects (but would return for a brief guest appearance in 2007).