- "You don't understand. No one understands true love."
- ―Kroon explaining his motive for murder
Peter Kroon appears in The Princess and the Pear.
A medieval historian and blacksmith knowledgeable on fighting styles of the period due to his studies at high brow universities (such as Oxford), Kroon found the famous Excalibur prop sword from Le Morte d'Arthur. Instead of selling the sword, Kroon would give it to fellow geek Kendra Kim as a show of love. Kendra, instead of keeping the sword, placed it onto auction. This angered Kroon - who murdered Kendra using a pear of anguish (a Medieval torture device) and hid her body in a sewer tunnel.
After Kendra's body was found, Brennan and Booth's investigation of Kendra's murder pointed towards ImagiCon - a fantasy convention that Kroon was present at. They would find out the link between the fake Excalibur and Kendra and buy it in a rigged auction. Kroon found out about this and attacked them by ramming Bones' car off the road and then ambushing Bones (and Sweets) while wearing his Black Knight armour to reclaim the sword. This would fail due to Bones fighting Kroon off with the Excalibur. Kroon was injured in the process - bleeding onto the Excalibur and leaving behind a fragment of his armour. This would lead to his arrest. Kroon would crack within the interrogation and be arrested for her murder.