『一個朋友的媽媽2』介紹:香(xiang)港警隊被元(yuan)(yuan)(任賢齊 飾)率(lv)領的悍(han)匪打得無力還擊的一幕被電視(shi)(shi)(shi)攝制隊拍了(le)(le)下(xia)來,全(quan)港市民(min)嘩(hua)然。為(wei)了(le)(le)聲譽(yu),全(quan)港3萬多的警員(yuan)(yuan)都(dou)投入(ru)到(dao)(dao)緝拿重犯的行動中。重案(an)組督察(cha)恒(heng)(heng)(張家輝 飾)跟蹤元(yuan)(yuan)到(dao)(dao)了(le)(le)一棟大(da)廈,在他(ta)們正(zheng)想行動時,副指揮官(guan)Rebecca(陳(chen)慧琳 飾)卻(que)打算(suan)把整個過(guo)程通(tong)過(guo)電視(shi)(shi)(shi)現場(chang)直播。恒(heng)(heng)與其他(ta)隊員(yuan)(yuan)都(dou)帶上(shang)了(le)(le)微型攝影(ying)機沖(chong)入(ru)了(le)(le)現場(chang),大(da)廈內早(zao)已躲著另(ling)一班(ban)劫匪,形勢兇險(xian),Rebecca卻(que)想剪掉此(ci)片(pian)斷(duan)。在大(da)廈內挾(xie)持人(ren)質(zhi)(zhi)的元(yuan)(yuan)把在閉路電視(shi)(shi)(shi)上(shang)錄(lu)到(dao)(dao)的警匪搏(bo)擊片(pian)段(duan)發給了(le)(le)傳媒(mei),警方更加(jia)尷(gan)尬了(le)(le)。元(yuan)(yuan)挾(xie)持人(ren)質(zhi)(zhi)對抗警察(cha),恒(heng)(heng)救出了(le)(le)人(ren)質(zhi)(zhi),逃跑了(le)(le)的元(yuan)(yuan)遇到(dao)(dao)了(le)(le)Rebecca,Rebecca從未見過(guo)恒(heng)(heng)跟元(yuan)(yuan),便誤以為(wei)元(yuan)(yuan)是警察(cha)恒(heng)(heng),元(yuan)(yuan)將計(ji)就計(ji),想借(jie)此(ci)脫(tuo)身。