Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Justin Quayle, a low-level British diplomat and horticultural hobbyist posted in Kenya, learns that his wife Tessa was found dead in the veld. Tessa has been murdered at a crossroads along with her Kenyan driver. Her colleague, Dr. Arnold Bluhm, initially suspected of her murder, is then found to have been murdered on the same day as Tessa. Various rumours abound that the two were having an affair; it is later revealed that Bluhm was gay.
In flashbacks, we see how in London, Justin met his future wife Tessa, an outspoken humanitarian and Amnesty International activist. He falls in love with her, and she persuades him to take her back with him to Kenya. Despite their loving marriage, Tessa keeps from Justin the reason why she approached him in the first place: to investigate a suspicious drug trial in Kenya and expose it. When Tessa starts getting too close to uncovering the malpractices of an influential and powerful pharmaceutical company, she and her colleague are brutally murdered.
As the mystery surrounding his wife's death unfolds, Justin becomes determined to get to the bottom of her murder. He soon runs up against a drug corporation that is using Kenya's population for fraudulent testing of a tuberculosis drug. The drug has known harmful side effects, but the corporation completely disregards the well-being of its impoverished African test subjects.
What is the last name of the person who was murdered?