The paperback copy of The Time Machine by H.G. Wells started as a subtle hint in the final season of the series, but ended up playing a major part of the finale's message about Jimmy/Saul/Gene. First seen among the items abandoned in Saul's house, we later see him reading it before bed. In the final episode, we are shown multiple scenes of Saul asking characters what they would do with a time machine. Towards the end, the true meaning and relevance of the question and book are shown to us.