Atoc was an Inca who appeared in Evil Star.
Atoc's brother, Micos, attacks Matthew Freeman and Richard Cole's chauffeured car. Richard fights them off long enough for Matt to escape, but he does not know that they are the Incas who are trying to help him.
Atoc saves Matt and Pedro from being captured by the corrupt police who are working for Diego Salamanda. He takes them down an underground tunnel where they travel to Cuzco. They then take a helicopter and then walk up to Vilcabamba, the sacred home of the Incas.
Atoc and the Incas, along with Matt, Pedro and Richard ambush Salamanda's research center but many Incas die in the process and Salamanda is not there.
Atoc successfully saves Matt and Pedro, when their helicopter is shot down over the Nazca desert by Salamanda. It spins out of control, but Atoc manages to crash-land it, saving Matt and Pedro but he is unable to save himself.
Richard Cole suddenly sees him when he is arguing with Matt about his safety. Even though he only saw a hood and goggles, he saw his smile and Richard catches a quick glimpse. Something that Richard would remember later on, perhaps foreshadowing the sacrifice Richard has to make for Matt with the sacrifical tumi that The Incas gave him.
Micos is his brother and he is deeply upset when he learns from Matthew Freeman that he died. But finds some consolation from the fact that Micos was shot whilst helping Matt and Pedro escape from Salamanda's house.