Eye in the Sky (traditional Chinese: 跟蹤; simplified Chinese: 跟踪, Literally: Tracing) is a 2007 Hong Kong action thriller film starring Simon Yam, Tony Leung Ka-fai and Miss Hong Kong pageant winner Kate Tsui in her film debut. Yam and Tsui play surveillance operatives on the trail of a gang of professional robbers led by Chan Chong-Shan (Leung). The title is derived from the casino surveillance tech "eye in the sky". It marks the directorial debut of Yau Nai-hoi, a long-time screenwriter for films directed by Johnnie To, who co-produced the film with his production company Milkyway Image. Eye in the Sky premiered as an Official Selection at the 2007 Berlin International Film Festival, and as an Opening Film at the Hong Kong International Film Festival. It was released by Edko Films in Hong Kong on 21 June 2007.