Henry Slesar was best known for the hundreds of mystery stories he wrote under the pseudonym O. H. Leslie. He began writing short stories in the mid-1950s while working as a copywriter for an ad agency. In the late 1950s and early 1960s he began writing for film and television. He wrote several episodes of "Alfred Hitchcock Presents" and "The Alfred Hitchcock Hour" during that time, developing a for writing eerie stories with multiple plot twists and turns. Following his work with "The Alfred Hitchcock Hour", he wrote the screenplay for the 1965 film "Two on a Guillotine", which was quickly followed by another crime-mystery film, 1966's "One of Our Spies Is Missing". Later in 1966 he returned to television writing episodes for the Golden Globe-nominated drama "Run for Your Life". He started writing for the soap opera "The Edge of Night" in 1968, continued until the early '80s, and garnered a Daytime Emmy Award for his efforts. He continued to write for television in the 1970s and 1980s with works like "Tales of the Unexpected" and the reboot of "Alfred Hitchcock Presents" in 1985. Later in his career, during the 1990s and early 2000s, Slesar wrote only screenplays for films and for shorts like "The Maddening", "Die Prufung", and "Heartbreak Hospital", which proved to be his final writing credit. Slesar died following complications from surgery in, 2002.