After the killing of the two sensible members of the group, namely Piggy and Simon, Ralph is relentlessly pursued by Jack.

relentlessly 是由形容词 relentless（无情的、残酷的）加上后缀 -ly 构成的副词形式。relentless 由前缀 re-（表示"再次"）和拉丁词根 lent（意为"弯曲、屈服"）组成，字面意思是"不屈服、不放松的"。relentlessly 表示"无情地、毫不松懈地"，形容追捕行为持续不断且毫不留情。