The lighthouse symbolizes the elusive nature of right and wrong. As the light rotates, it illuminates only one aspect while leaving the rest temporarily in darkness; the movement of the light demonstrates that what seems right in one moment could easily seem wrong in the next.

The lighthouse, at different points, symbolizes safety for some but danger for others. Tom sees the lighthouse as a safe place after the war, a place where he can be alone and his perceptions of right and wrong are clearly defined. This clarity is a relief to Tom after the moral ambiguity of war. Once he brings Isabel to Janus, however, the safety of lighthouse is less certain.

The lighthouse comes to symbolize danger, signaling ships to stay away, lest they be destroyed on the rocky shores of the island. The isolation of Janus’s lighthouse has created an opportunity for Tom and Isabel to pretend that right and wrong do not exist, that one can act without consequence; this escape from reality proves dangerous when Lucy appears on the shore of Janus Rock in the boat on that fateful day.