Description: The series takes place a few months after the 3rd installment.

Chan Siu Sang (Bobby Au-Yeung) and Wai Ying Zi (Ada Choi) have been dating for a while and seems to be in a stable relationship. Everything seems to be looking up for Ying Zi now that she’s in a stable relationship and finally got a promotion at work, but the only that she and Siu Sang seem to fight about is marriage. He wants to rush into marriage but she wants to put it off for a few years to focus on her career since it is flourishing. Their relationship is further complicated when Siu Sang becomes jealous of Ying Zi’s new handsome co-worker Ken (Frankie Lam), Mad that Siu Sang does not trust her, the two decide to break up. Ying Zi soon starts dating Ken since the two grew close while working together and Siu Sang begins dating Sunnie (Yoyo Mung) who works at the forensic department after being pursued by her.

Having gone through so many tragedies in the past Chan Sam Yuen (Joyce Tang) finally decides to focus on her family as top priority. She and Ching Fung (Marco Ngai) have patched up their marriage even though it is still not perfect. With a difficult pregnancy Sum Yuen is no longer focus on her career. All seems well with her and Fung when she gives birth to a son until Fung gets entangled with female triad boss Chiang Tin Wing and her husband Sing Jin Choi. Fung is in charge of the case of Wing and her crime empire. While investigating Wing, she takes a liking to Fung and drugs him so she can have her ways with him. She uses their one night of passion to blackmail Fung into continuing their affair. Choi finds out about the affair between his wife and Fung, enraged with his wife’s infidelity he accidentally kills her and frames Fung for her murder. With evidence to clear Fung of the crime Choi decides to kill Fung as revenge for ruining his marriage.
Language: Cantonese
Production company(s): TVB
Country: Hong Kong
Times: 40 Episodes
Release Date: 2004
Cast: Bobby Au-yeung, Ada Choi, Joyce Tang, Marco Ngai, Mimi Chu, Frankie Lam, Yoyo Mung

• Armed Reaction IV – 陀槍師姐 IV
• Armed Reaction IV – 陀槍師姐 IV – Episode 40
• Armed Reaction IV – 陀槍師姐 IV – Episode 39
• Armed Reaction IV – 陀槍師姐 IV – Episode 38
• Armed Reaction IV – 陀槍師姐 IV – Episode 37
• Armed Reaction IV – 陀槍師姐 IV – Episode 36
• Armed Reaction IV – 陀槍師姐 IV – Episode 35
• Armed Reaction IV – 陀槍師姐 IV – Episode 34
• Armed Reaction IV – 陀槍師姐 IV – Episode 33
• Armed Reaction IV – 陀槍師姐 IV – Episode 32
• Armed Reaction IV – 陀槍師姐 IV – Episode 31
• Armed Reaction IV – 陀槍師姐 IV – Episode 30
• Armed Reaction IV – 陀槍師姐 IV – Episode 29
• Armed Reaction IV – 陀槍師姐 IV – Episode 28
• Armed Reaction IV – 陀槍師姐 IV – Episode 27
• Armed Reaction IV – 陀槍師姐 IV – Episode 26
• Armed Reaction IV – 陀槍師姐 IV – Episode 25
• Armed Reaction IV – 陀槍師姐 IV – Episode 24
• Armed Reaction IV – 陀槍師姐 IV – Episode 23
• Armed Reaction IV – 陀槍師姐 IV – Episode 22
• Armed Reaction IV – 陀槍師姐 IV – Episode 21
• Armed Reaction IV – 陀槍師姐 IV – Episode 20
• Armed Reaction IV – 陀槍師姐 IV – Episode 19
• Armed Reaction IV – 陀槍師姐 IV – Episode 18
• Armed Reaction IV – 陀槍師姐 IV – Episode 17
• Armed Reaction IV – 陀槍師姐 IV – Episode 16
• Armed Reaction IV – 陀槍師姐 IV – Episode 15
• Armed Reaction IV – 陀槍師姐 IV – Episode 14
• Armed Reaction IV – 陀槍師姐 IV – Episode 13
• Armed Reaction IV – 陀槍師姐 IV – Episode 12
• Armed Reaction IV – 陀槍師姐 IV – Episode 11
• Armed Reaction IV – 陀槍師姐 IV – Episode 10
• Armed Reaction IV – 陀槍師姐 IV – Episode 09
• Armed Reaction IV – 陀槍師姐 IV – Episode 08
• Armed Reaction IV – 陀槍師姐 IV – Episode 07
• Armed Reaction IV – 陀槍師姐 IV – Episode 06
• Armed Reaction IV – 陀槍師姐 IV – Episode 05
• Armed Reaction IV – 陀槍師姐 IV – Episode 04
• Armed Reaction IV – 陀槍師姐 IV – Episode 03
• Armed Reaction IV – 陀槍師姐 IV – Episode 02
• Armed Reaction IV – 陀槍師姐 IV – Episode 01