Armed Reaction - Armed Reaction IV

Chan Siu Sang and Wai Ying Zi have been dating for a while and seem 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. Their relationship is further complicated when Siu Sang becomes jealous of Ying Zi's new handsome co-worker Ken. 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, who works in the forensic department, after being pursued by her.

Having gone through so many tragedies in the past, Chan Sam Yuen finally decides to focus on her family as a top priority. She and Ching Fung have patched up their marriage even though it is still not perfect. With a difficult pregnancy, Sum Yuen is no longer focused on her career.