Anonymous Signal

Main Role

• 
  Joel Chan

  Kwok Pak Fei

  Main Role
• 
  Moon Lau

  Keung Hei Man

  Main Role
• 
  Owen Cheung

  Chiu Chun Long

  Main Role
• 
  Tiffany Lau

  Wan Ka Lei

  Main Role

Support Role

• 
  Karl Ting

  Fong Tze Chiu

  Support Role
• 
  Rosita Kwok

  Seung Seung

  Support Role
• 
  Alex Lam

  Lau Lik

  Support Role
• 
  Carlo Ng

  Seung Dong [Seung Seung's father]

  Support Role
• 
  Miumiu Au

  Law Yui Yui

  Support Role
• 
  Rosanne Lui

  Seung Sin [Pak Fei's mother]

  Support Role
• 
  Amy Fan

  Keung Chin Kiu [Hei Man's cousin]

  Support Role
• 
  Mary Hon

  Chiu Seung Ngo [Tze Chiu's mother]

  Support Role
• 
  Cheung Kwok Keung

  Kwan Chan Yu

  Support Role
• 
  Brian Tse

  Lee Kin Wo / "Wo Sze Lo"

  Support Role
• 
  Henry Lo

  Fong Bing Keun [Tze Chiu's father]

  Support Role
• 
  Man Yeung

  Si Tou But [ASIB]

  Support Role
• 
  Fei Wong

  Kam Jing Yi [ASIB]

  Support Role
• 
  Kelvin Yuen

  Leung Chi Ming [ASIB]

  Support Role
• 
  Jerry Leung

  Lee Hou Nam [ASIB]

  Support Role
• 
  Sunny Dia

  Wong Kwok Kei

  Support Role
• 
  Curtis Ho

  Fong Yu On

  Support Role
• 
  Carina Leung

  Lam Chi Mei

  Support Role

Guest Role

• 
  Irina Tang

  Ma Mei Ling (Ep. 1)

  Guest Role
• 
  Milkson Fong

  Cheng Fai Kei (Ep. 1)

  Guest Role
• 
  Eddie Li

  Lui Gong (Ep. 1)

  Guest Role
• 
  KC Wu

  Wu Gwai (Ep. 1)

  Guest Role
• 
  Hugo Wong

  Lok Chan Wah (Ep. 1-4)

  Guest Role
• 
  Bond Chan

  Sung Yiu Hing (Ep. 1-4)

  Guest Role
• 
  Fanny Lee

  Director Yim (Ep. 2)

  Guest Role
• 
  Janice Shum

  [Hiu Wai's mother] (Ep. 2)

  Guest Role
• 
  So Lai Ming

  Fung Siu Cheung (Ep. 4, 6)

  Guest Role
• 
  Lenna Yeung

  Lau Suk Keun (Ep. 4-7)

  Guest Role
• 
  Eric Tang

  Zeng Yik Hei [Nurse] (Ep. 4-7)

  Guest Role
• 
  Keith Mok

  Kwok Mun (Ep. 5-6)

  Guest Role
• 
  Tse Ho Yat

  Tang Sai Long (Ep. 7-8, 10)

  Guest Role
• 
  Arnold Kwok

  Lai Yin Dak (Ep. 7-10)

  Guest Role
• 
  Ceci Mak

  Chiang Ting Ka (Ep. 7-10)

  Guest Role
• 
  Junior Anderson

  [Doctor] (Ep. 8)

  Guest Role
• 
  Ng Shui Ting

  Chiang Kai Sing (Ep. 8-10)

  Guest Role
• 
  Lucas Yiu

  Tang Sai Fu (Ep. 8-10)

  Guest Role
• 
  Matthew Chu

  Wong Kam Lun (Ep. 9-10)

  Guest Role
• 
  Leo Kwan

  Hui Yu Sung (Ep. 11-12, 14)

  Guest Role
• 
  King Lam

  Mang Geng Bo (Ep. 12-13)

  Guest Role
• 
  Andy Sui

  Chiu (Ep. 12-13)

  Guest Role
• 
  Kinlas Chan

  Chan (Ep. 12-13)

  Guest Role
• 
  William Chu

  Yeung (Ep. 12-13)

  Guest Role
• 
  Joan Lee

  Koo Siu Lai (Ep. 12-14)

  Guest Role
• 
  Lincoln Hui

  Bin King Hoi (Ep. 13-14)

  Guest Role
• 
  Danny Lo

  Wong Dak Qun (Ep. 14)

  Guest Role
• 
  Andy Wong

  Sam Hin Wai (Ep. 14)

  Guest Role
• 
  Eddie Ho

  Liu Hiu Tong (Ep. 14)

  Guest Role
• 
  Kitterick Yiu

  Fung Kei (Ep. 14)

  Guest Role
• 
  Fanny Ip

  [King Hoi's mother] (Ep. 14)

  Guest Role
• 
  Akai Lee

  A Tim / "Tim" (Ep. 15)

  Guest Role
• 
  Sean Li

  Kam Zak (Ep. 15-16)

  Guest Role
• 
  Terrence Huang

  Fan Gwat (Ep. 15-16)

  Guest Role
• 
  Nicole Wan

  Hong Na (Ep. 17-18)

  Guest Role
• 
  Clementine Sze

  Li Bing Suet (Ep. 17-18)

  Guest Role
• 
  Gordon Ip

  Ting Yut Sing (Ep. 17-19)

  Guest Role
• 
  Derek Wong

  Chan Wing (Ep. 17-19)

  Guest Role
• 
  Sophia Lam

  Keung Hei Man [Child] (Ep. 21-22)

  Guest Role
• 
  Jim Tang

  Fong Bing Keun [Young] (Ep. 22)

  Guest Role
• 
  Doris Chow

  Chiu Seung Ngo [Young] (Ep. 22)

  Guest Role
• 
  Sophie Yip

  Lau Wai Fong (Ep. 22-25)

  Guest Role
• 
  Bob Cheung

  Ling Lit (Ep. 22-25, 27-28, 30)

  Guest Role
• 
  Randal Tsang

  Kao Dun (Ep. 27-28, 30)

  Guest Role
• 
  Marco Lee

  Ngai Tit (Ep. 27)

  Guest Role
• 
  Parkman Wong

  Law Yau Bong [Yui Yui's father]

  Guest Role
• 
  Lisa-Marie Tse

  [Killer] (Ep. 30)

  Guest Role
• 
  Hero Yuen

  [Killer] (Ep. 30)

  Guest Role
• 
  Tony Chui

  [Sponsor] (Ep. 30)

  Guest Role
• 
  Vincent Cheung

  [Sponsor] (Ep. 30)

  Guest Role
• 
  Andy Lau

  Shing

  Guest Role
• 
  Axity Chong

  Hon Fung

  Guest Role
• 
  Maggie Leung

  [Reporter] | [Guest]

  Guest Role
• 
  Clare Chan

  Wan Nei

  Guest Role
• 
  Eden Lau

  Daai Kit

  Guest Role
• 
  Lau Cheuk Yan

  [Police officer in uniform]

  Guest Role
• 
  Bambi Lok

  (Ep. 1-2)

  Guest Role

Cameo

• 
  Kenneth Ma

  Tindy (Ep. 30)

  Cameo