Casper Wyoming (a.k.a Carmine Gowspy, alias in Mission 11: Behind Enemy Lines ) is a Vesper who tracked Amy and Dan to Switzerland in an attempt to steal Gideon's Ring in Vespers Rising. He is considered extremely dangerous. He is said to be one of the highest ranking Vespers, though he is not in the Council of Six. He was Vesper Six, but was removed and was replaced by his twin because he failed the mission.
- Hand-to-Hand Combat.
- Physical Strength.
- Use of Explosives.
Casper was named after the location of one of his parents' most successful bank robberies. By the time Casper was 17, he had an extensive criminal record and was wanted by the FBI. He later became a Vesper with a wish to become Vesper One.
Vespers Rising is Casper's first appearance, as it is the first appearance of the Vespers. He appears in the present day part of the book--Amy and Dan Cahill. He was one of the Vespers who was sent to obtain Gideon's Ring. He tracked down Amy, Dan and Fiske to the mountains in Zermatt, Switzerland and got to them just in time when they had discovered it. He demonstrated superior combat skills against Fiske and proceeded to chase Dan and Amy out on the mountain. They outran him into a cable car but he went after them in a helicopter along with Bruno, another Vesper agent and tried to kill Amy and Dan by cutting the cables with the helicopter blades. They were saved just in the nick of time by a police helicopter. Later, they escaped and engaged in a skiing chase with Amy and Dan. They were captured but were once again saved in the nick of time, this time by Fiske and Erasmus, who attacked Casper on skis and snowboard. Dan and Amy were rescued and the Vespers went back underground.
He was one of the motorcycle gang which steals the Medusa off Dan and Amy.
After Cheyenne loses track of the Cahills, the two pursue them to a castle where Cheyenne distracts Jonah and Hamilton while Casper traps the Cahills who just found the map with a knife. Amy kicks the knife out of his hand but Casper produces another knife and threatens to kill one of the siblings. He is then stopped by Jonah's fans. He and his sister later pursue the Cahills to the library Katja Mavel works at. Cheyenne holds Atticus although Jake tries to stop her. Casper and Cheyenne lock Dan and Amy in a sealed room where they are in danger of losing oxygen. The Wyomings then flee after Dan and Amy escape. When Dan and Amy are later delivering the map Casper swoops by and takes Atticus hostage and elbows Dan in the throat.
Casper organizes the jet which takes Atticus to Turkey. He threatens Atticus with a knife. Then Atticus threatens him with a pistol. Casper is revealed to have a fear of bats. Casper appears by the Cahills' car and tells to step aside so he can shoot Atticus. He then tells them he doesn't care what happens to them and that he is as good as dead.
Casper and Cheyenne stole "The Book of Ingenious Device" from the Pergamon Museum while Amy and Dan are trying to steal the Golden Jubilee Diamond. Later he and Cheyenne follow Amy and Dan to Timbuktu to find the "Apology".
Casper first appears along with Cheyenne when she kidnapped Jonah, Phoenix, Evan and Ian. He escorts Ian to a meeting with his mother, Isabel. When they stop at location of the Machina Fini Mundi, he is knocked unconscious by the hostages. He, along with his sister, Cheyenne, later gets pepper sprayed in the face by Sandy for betraying Vesper One. He is later seen tied to a pole in a room full of crashing water. He, Cheyenne and Sandy Bancroft are later sent to jail.
Casper currently has no cards, though he appears on Card 266 along with his sister Cheyenne Wyoming.
- His dream was to one day be Vesper One.
- He is suspected of having been on the Council of Six in the past, but was confirmed in A King's Ransom that he is not currently in the Council.
- He has a tremendous fear of bats.
- He has a purple triceratops tattoo on his wrist, just like Cheyenne.
- He dressed up as a bank guard called Bachmann in Vespers Rising.
- Apart from the Council of Six, he might be the only other Vesper to know who Vesper One was.
- He is named after a successful bank robbery of his parents'.
- One of his aliases include Carmine Gowspy, as revealed in Mission 11.
- He, Cheyenne, and Sandy Bancroft are arrested by the authorities.