For 14 months, the Eritrean army - including 40,000 women - has been at war with Ethiopia. At least 50,000 people have died since a border skirmish in May last year escalated into a full-scale war along the border which separates the two neighbours in the Horn of Africa.
To Tekeste and her fellow fighters from 491 Division, stationed along the 150km Tsorona front, the war is about safeguarding Eritrea's independence - won in 1993 after a 30-year guerrilla war with Ethiopia. Their commitment is unquestioning. They know no other way than nationalism, because every family in this nation of 3.5 million people had a part in the independence war.
"I have been fighting for a year and I have never been back to Asmara [the Eritrean capital] to see my family," says Tekeste, who had finished high school and begun her national service when the war started.
"My mother writes to me but I do not write back. If I tell them I am in Tsorona and they hear of something happening here, they will worry. If I come back from the war, they will be happy. My father fought in the independence war, so I know," she says, to approving nods from her comrades.
We are hunched in a two-metre-square underground dug-out - a kind of siding off the trench - where Tekeste and her mess-mate, Nuguse Hailab, 25, have slept for the past three nights. He is not her boyfriend. "They are all my boyfriends," she jokes.
Overhead, tree trunks have been laid to cover the sleeping area. The Ethiopians are about 400m away but there has not been intense fighting lately. Every day, Tekeste and her team rise at 4am for a two-hour shift on full alert. They keep a similar watch between 6pm and 10pm. The daylight hours are filled with digging new trenches - the rainy season is beginning, so they must prepare for floods.
Tekeste is one of three women in her mess of 13. She claims that all tasks are performed by both sexes. But it is clear that, for commanding officers on the front line, women always light the fires and prepare the tea.
Seasoned male fighters say that the women are the most ruthless. But it is also whispered that, while the powerful moral pressure to join up prevails, women on the front who become pregnant are delighted to have an excuse to leave. Indeed, sex is probably one of the few pleasures available to Tekeste and her comrades.
It is hard to fathom Tekeste, with her girlish face, dainty earrings, soft voice, hair in a bun and big, baggy combat khakis. All around, the scrub landscape is littered with burnt-out vehicles and mementoes of the dead - photographs, boots, buttons and caps.
"We do not feel anything about the bodies," she says.Dozens of corpses are left to decompose between the Eritrean and Ethiopian lines. This landscape of horror is where Tekeste sleeps, eats - and listens to Mariah Carey.
Alex Duval Smith