The lighthouse is on an island called Janus, and the lighthouse keeper explains that it is named for the two-faced god who is memorialized in the first month of each year, January. One face looks to the past, the other to the future -- "two ways of looking at things." The theme of duality and perspective resonates throughout this story of the lighthouse keeper, Tom Sherbourne (Michael Fassbender) and his wife Isabel (Alicia Vikander), we see how two ways of looking at things can balance or...