When the doctor first met Suki, she was astounded by Suki's adventurous spirit and tendency to engage in risky, thrilling activities like skydiving, rafting, and mountain climbing. However, as the two fell in love, the doctor quickly learned Suki's fearlessness stemmed from the fact that her life already had an expiration date — she had been diagnosed with an advanced stage of cancer. After Suki's death, the doctor and Suki's old friends continue their adventures. During a skydiving expedition alongside the doctor's new lover, Cate, things go awry. They're in Mexico, and when they dive into the rainforest, gigantic Quetzalcoatl monsters attack and kill many of the skydivers. The doctor survives but falls into a deep pit called a cenote, known to nearby rainforest villages as a portal to the underworld. In the darkness, Suki appears. She beckons to the doctor to join her. Instead, the doctor decides to climb from the cenote to rejoin Cate in the land of the living; she chooses her future happiness over her past love.