Valerie pulls a pair of blue shorts and a small white shirt out of a plastic bag. The shirt is stained with blood. It's the school uniform of her eight-year-old son Nathanael, who was kidnapped on his way to class in Goma in the Democratic Republic of Congo.
The capital of the troubled North Kivu province in the east of the vast African country has seen a surge in children being kidnapped, tortured, and sometimes even killed.
Nathanael's kidnappers demanded a four-figure ransom, in dollars -- a sum that his single mother in her 30s, who has no fixed income, could not possibly afford to pay, although they do live in a large house provided by one of Valerie's parents.
"It was definitely a Monday," says Valerie of the day when her nightmare began. She cannot be certain if it was in July or August of this year, although everything else is seared into her memory.
On the Tuesday the kidnapper said over the phone: "Give us $5,000 (4,250 euros) or you will find your son's body on your doorstep."
On the Wednesday, Valerie scraped together 20 dollars and sent it by Airtel Money, a mobile phone money transfer system widely used in Africa. After the meagre sum was dispatched, her son screamed over the phone: "Mum, they're killing me!"
On the Sunday, Nathanael was released with an earlobe sliced in half and stab wounds on his arms, his mother said. He told her another child was killed in front of him during his detention.
- 'Due to poverty' -
Goma, a city of about a million people, sits in a tourist-friendly location between a lake and a mountain.
But it has endured a brutal recent history -- the fallout from the Rwandan genocide, the eruption of the Nyiragongo volcano in 2002 and the mutiny of the rebel group M23 a decade later.
The area is also riven by fighting between armed rebel groups.
Jean-Paul Lumbulumbu, a well-known lawyer in Goma, said he represented a total of 20 families who have fallen prey to kidnappers, including one or two cases in which children were killed.
The kidnappings started in Goma earlier this year, the lawyer said, citing two videos on his phone as evidence.
In the first video, the lawyer conducted a sit-in on August 11 calling on the authorities and police to act against delinquency in general.
In the second, he expressed satisfaction at a report that three kidnappers were sentenced to 20 years in jail. One of the kidnapped children was killed, judges said during the trial, according to the report by UN station Okapi.
"It has been about a year since this phenomenon began in this city," a police source told AFP.
"In my humble opinion, I would say that it is the economic situation that drives people to such criminal practices. It is due to poverty," the source added.
- Nightmares -
Previously in North Kivu, abductions were normally adults being taken by one of the armed groups active in the region.
But now "the modus operandi is always the same. They torture the child so that the parents give them something," the police source said.
The police are attempting to track the kidnappers by asking telephone companies for the identity of suspects, who receive ransom money by using lots of SIM cards to cover their tracks.
As night falls on Valerie's large living room, the light is not turned on, probably to save money. In a corner, Nathanael's sister and two brothers play in the light of a mobile phone, listening as their mother recounts her story in Swahili.
As for Nathanael, "he went back to school, but the teacher suggested that he rest," his mother says.
"At night he has nightmares, shouting 'Achab!'" -- the name of the child who was murdered in front of him.