Blood Oath
 "Blood Oath" opens with an Army Ranger task force in Kosovo, conducting surveillance on a group of Serbians as night falls. The Rangers watch as a mysterious figure attempts to bargain with the Serbs, trading a bag of cash for a mysterious case with US Army markings. However the deal goes bad and the Serbs attack the figure. As the fight progresses, one of the soldiers sees the fight between the figure and a Serb up close, and realizes what he is seeing: a werewolf and a vampire, in a fight to the death. Twenty hours later, Griff is escorting Zach Barrows to the Smithsonian Institution. There, Zach meets the mysterious figure: Nathaniel Cade, a vampire bound by a blood oath to serve the President of the United States. Agent Griff is retiring, and brings in Zach to take over after Zach is found fooling around with the president's daughter. Through various flash-backs, we find out about Cade's past: as a young man, he served on a whale hunting vessel in 1867. His ship was attacked by a vampire, killing all on board but leaving Cade, who turned to a vampire himself. He was captured and sentenced to death, but spared by President Andrew Johnson, who in turn had him bound by voodoo to the Office of the President. As Zach begins his first day, he and Cade are dispatched to the Port of Baltimore. ICE agents have found a shipping container holding a horrible discovery: various body parts, all hanging on hooks in a grim meat locker. After interrogating the driver, Cade tells Zach that they are on their way to find Johann Konrad Dippel, the real-life Dr. Frankenstein. Konrad is an alchemist from Germany, and is currently over 350 years old, due to having discovered the Elixir of Life. His Elixir can bring dead tissue to life, and make it so strong just one of his creations killed dozens of people before being stopped. Konrad had been arrested in Nigeria by Cade in 1970; however, Konrad performs a service to the United States in 1981 and as a result is set free, as long as he does not practice his evil medicine again. Cade and Zach confront Konrad, who denies any involvement with the dead body parts. However, after Cade and Zach leave, Konrad moves to a secret lab and proceeds to demonstrate that he has not given up his diabolical work at all. Cade leaves Zach to tail Konrad while he finds an Alcoholics Anonymous meeting to attend. At the A.A. meetings, Cade is able to draw strength from the humans, as they all struggle with desire for the drink, even if they have different thirsts. As Cade leaves, he is stopped by Tania, a female vampire he failed to help in the past. While neither will admit it, their shared history gives them both the closest thing to feelings for each other that vampires can feel. As Zach is tailing Konrad, he is followed by a mysterious black car. With Cade's assistance, they ambush the black car and find Helen Holt, a former CIA agent who now works for a dark organization referred to as Shadow Company. The Shadow Company began during the Cold War, and has since delved into darkness so deep that the conspiracy theories about President John F. Kennedy and Roswell are nothing compared to the truth of what they truly do. As Cade and Zach dig deeper and deeper into the truth behind the body parts and their connection to Konrad, they find back-stabbing and double-crosses waiting for them at every turn, with their search finally ending in a terrifying showdown with the Other Side that takes place in the heart of the nation's capital.