An SUV driven by a Middle Eastern man explodes in front of a busy Washington DC cafÃ©. Dr. Temperance Brennan, a forensic anthropologist, Angela Montenegro, her reconstruction artist, and her assistant Zack Addy arrive at the scene. The Middle Eastern man is identified by Homeland Security as Hamid Masruk. Brennan is asked to confirm the identity.
Evidence shows that Masruk suffered from an unknown medical condition that produced lesions on his face. His brother Farid shares the condition, and tells Booth and Brennan that it is genetic.
Back at the lab the squints reassemble the body. Zack debrides the flesh from the skeleton using dermestes maculates.
Jack Hodgins, an entomologist who is also an expert in particulates, finds perchloratein Hamid's clothes.
Examining the debrided skeleton, Dr. Brennan looks for points of identification, comparing what she finds to Hamid's medical records. She finds the skeleton's texture of pubic symphysis is consistent with Masruk. Uneven growth patterns in the bone indicate malnourishment as a child. Evidence of multiple past fractures on the bottoms of the feet are consistent with methods of torture used in Afghanistan and with Masruk's history. Dr. Brennan tells Zack to do a cranial reconstruction, but she is convinced this is Hamid Masruk.
Zack runs into trouble reconstructing the skull. The ethmoid and sphenoid fragments won't piece together. The integrity of the bone seems compromised. Brennan examines the skull and finds unusually soft bone tissue. She finds a disorganized trabecular pattern in the bone. She thinks Masruk may have suffered from a degenerative disease. She tells Hodgins to check for Paget's disease and Lupus. He is negative for both. Brennan has them check for environmental contaminants.
Hodgins and Zack find gypsum in the bones. It is non-toxic and wouldn't damage the bones. It was probably used to insulate the explosives. They start to reconstruct the bomb, looking to identify what it was made from.
Brennan finds microscopic fissures in the trabecular pattern of Hamid's skull. This proves Hamid was exposed to a toxin before he died. She has Hodgins check the marrow but it's degraded. Hodgins dissects the beetles that ate Hamid's flesh and find traces of dioxin.He and Zack also tie the gypsum they found to a type of plaster used in pyrobar, a kind of fire-proof tile developed in 1903 by the United States Gypsum Company. By researching where in DC this tile was used, they are able to identify where the bomb was built, and thus the bomber, Hamid's brother, Farid Masruk.