Voice - Season 2 - Eps 4: Shh! It's a Customer's Secret (1)
With Kwak Min Soo in the grasp of law enforcement, the situation is turned on its head when someone gets through their safe walls. An old man finds the suicide of his friend, but nothing is as it seems.
About Voice

Title: Voice
First Air Date: 2017-01-14
Last Air Date: 2021-07-31
Status: Ended
Rating: 7.2/10 (from 61 votes)
Language: KO
Seasons: 5
Total Episodes: 58
Network: OCN
Genres: Crime, Drama
Production Companies: Content K, Studio Dragon, KEYEAST
Synopsis
It's 3 minutes for hearers, but a life for the callers. A crime thriller chasing even the slightest sounds to rescue people's lives calling for urgent help.
Cast

Lee Ha-na
Kang Kwon-ju

Song Seung-heon
Derek Jo

Son Eun-seo
Park Eun-Soo

Kim Joong-ki
Park Joong-Ki

Baek Sung-hyun
Shim Dae-Sik

Song Boo-gun
Goo Gwang-Soo

Kang Seung-yoon
Han Woo-Joo

Maurice Turner Jr.
Nick Jackson

Kim Kyu-na