Natacha Antila was a Russian physician sent to assist the scientific group investigating the "erratics" in Siberia. She was put in charge of the infirmary tent, where she tended to patients. Before they left the camp, Antila gave Connor Temple and Abby Maitland a thorough medical examination, in order to make sure that they both had a clean bill of health.
Later on, when a Torosaurus attacked the jeeps, and Connor and Umarov were injured, they were both sent back to the medical tent, where they were being taken care of by Antila. She insisted that Connor stay in bed, but he refused, saying that he needed to work on his Anomaly Detector. However, in the end, the two of them reached a compromise: Connor would work on his Anomaly Detector inside the infirmary, where Natacha could watch him, at all times.
In the novel, Natacha Antila is described as being young, athletic, and very beautiful, with long, brown hair. It is proven that Connor has a crush on her, which makes Abby mad. In the past, Antila apparently had a relationship with Shvachko, which ended quite badly as it was hinted that he abused her. As such, she despises the very mention of his name and calls him "pig-man, with trotters and snout and long curly tail" among other things..
Natacha Antila remained in the infirmary for the rest of the book, until the Tyrannosaurus Rex attacked the camp. Antila saved Abby, Bulov, and Suvova, by using one of her surgical knives to cut a hole in the wall of the tent, allowing the four of them to escape. She also saves Connor and Koshkin from being shot by Shvachko by clobbering him from behind with a log.
In the end, she says goodbye to the British team, as they leave on a helicopter. Afterwards, she presumably remains at the research outpost. (Extinction Event)