McTiernan rules Rudolph out as Casanova, meaning he must be The Gentleman Caller. A manhunt for the killer begins, but he escapes several times and vanishes. A search of his apartment uncovers a picture of him with one Dr. Wick Sachs; notes on the back identify Sachs as Casanova. Cross and Sampson discuss a theory that the girls are being held in an underground house, built in an area that was part of the Underground Railroad. Sachs is a professor at Duke and known as the campus skeleton, as well as a suspect when two students were murdered in the early 1980s. Later Ruskin and Sikes ask Cross for help in catching Casanova, whom they believe to be Sachs. Rudolph reminisces how he met Casanova, who had known Rudolph had killed the young couple. They shared their experiences and formed a bond. When they reunite, they decide to work together to eliminate Cross. They attack McTiernan after she returns to her home, leaving her seriously wounded. Cross notices the attack is different from the first one and suspects both men worked together. The next day, Dr. Sachs is brought in for questioning. Cross attacks him physically, noticing that Sachs is not very strong, and Cross is sure that he is not Casanova. However, the FBI arrests Sachs nonetheless after finding evidence pointing to him. Sampson and Cross head to the forest again, taking a hand-written map given to them by an Underground Railroad historian. In a previously unsearched area, they find the underground house with the captive women. However, the two killers have been watching and assault them, seriously injuring Sampson. Cross shoots at them, hitting one in the shoulder. The two leave, stealing a truck. Cross pursues them and eventually forces them to separate. In the following gunfight, he kills Rudolph. The surviving women, including Naomi, are reunited with their loved ones. Cross looks for clues and deduces Casanova's true identity. Cross keeps the information from Agent Craig and decides to conduct his own stakeout. He follows Detective Sikes, positive that he is Casanova, looking for a new woman to kidnap. Cross snoops outside a house which Sikes has entered. Sikes sees him, and they fight. The woman turns out to be Sikes' mistress, an affair the FBI knew about. A while later, while visiting McTiernan, Cross goes jogging and finds a dead FBI agent. He runs back to