Rose thought she was coming to Europe to study and earn some money with a part-time job. What the Nigerian girl didn't realise was that books would be a distant dream and the work she would be doing was prostitution.
"Two people working in an apparently-normal travel agency arranged my journey. But once we arrived in Europe, we were locked in an apartment for a month and a half," she recounts. "They emptied our bags and seized our documents."
Sophie tells a similar tale. She thought she was coming to work in a shop or a factory to give her and her family a chance of a better life. She now makes 2,000 euros (US $2,400) a week -- something she could never have dreamed of back home in her village in Nigeria -- but the price she pays is selling her body.
“I thought I would be free in Europe," she says wistfully in the dark, tiny one-room flat she shares in the Italian port city of Genoa with two fellow sex workers.
There are no official figures but the International Office for Migration (IOM) estimates there 70,000 women living in Italy after being trafficked for sexual exploitation. And some local rights groups believe as many as half of them are Nigerian.
Traffickers demand on average more than 50,000 euros (US $60,000) for travel expenses and accommodation, with the girls having to work for them until the debt is paid off.
"I think in one year, I'll be able to pay my debt," said 24-year-old Naomi, who came to Italy to earn a living for her younger siblings after their parents died. "I will pay. I don't want to offend them. I know there will be so many problems down there if I don't."
That is a fear often held by women forced into prostitution, says Sister Valeria, who has spent time in Nigeria's Edo State, and now works with victims of trafficking in Italy. She says traffickers often coerce victims by exploiting their belief in voodoo rituals.
“They often make a sachet with the girl’s hair or underwear and even menstrual blood and they keep it,” she said. “Girls truly believe that if they reveal the names of these people or don’t pay them back, horrible things will happen to them and their families.”
Even before the girls arrive to discover the reality of their new life in Europe, they have often undergone excruciating journeys just to leave their home continent.
These days the high-priced voyage from West Africa to Europe is most often via the Sahara Desert, where it is easier for people to move about clandestinely with no papers.
“We walked for months,” said Sharon, one of Sophie's flatmates in Genoa, who made what she called a "merciless journey" through the desert to reach the northern tip of Africa from which she could take a boat to Europe.
“Many people died. Sometimes we would drink our urine,” she said shaking her head at the memory.
The plight of West Africans desperate for a chance at a better life in Europe has been under the media spotlight recently after several migrants were killed trying to scale a wall into Spanish enclaves in Morocco last month.
The incident and ensuing mass deportations of Africans pushed the issue to the fore at subsequent meetings in Brussels between African and European leaders.
During those meetings, the European Commission proposed that member states come up with a plan to strengthen efforts to prevent people being trafficked for sexual and labour exploitation.
But many people -- from former Malian president Alpha Oumar Konare to aid workers trying to combat the problem -- believe that the focus needs to be back in Africa, tackling the root cause of illegal immigration. Poverty.
"Exploitation feeds on poverty," says Sister Florence, who leads an organisation called the Committee for the Support of the Dignity of Women based in Benin City, southern Nigeria.
“We are hungry here,” she told IRIN. “The Nigerian economy is very bad and keeps getting worse every day. So children, especially daughters, become people’s source of income.”
Teresa Albano, who works for the IOM in Rome, says in nine out of ten cases, the families have signed their daughters away knowing full well what they are destined for.
“The girls are not free to decide for themselves and say no,” she said. “When the girls sign the ‘contracts,’ a family member has to be the guarantor, and there is always a clause that says girls will accept any job the organiser will offer in the destination country.”
For those girls who do want to break out of the bondage, there are few options. They are on Italian soil illegally with scant resources.
The only get-out that the Italian legal system provides is a "social protection residence permit", but that means denouncing your exploiters to the police, which is exactly what the girls fear.
According to the Caritas-Migrantes group, which studies immigration trends, only 999 of these permits were granted to Nigerian women between 1998 and 2004.
Another alternative is a repatriation programme, run by IOM, which can help women home on a voluntary basis. But there too, the way if fraught with problems.
"When the girls are released by the Nigerian police, after having undergone a mandatory HIV test, their traffickers are out there, ready to force them into the racket again," said Albano at the IOM.
And if they manage to dodge the traffickers, the girls can still run into to problems closer to home, says Sister Florence of the Benin City group.
"When the girls come back, they are expected to bring money and wealth and if they don't their families reject them and their trauma is twice as big," she explained.
But occasionally there are out-of-the-blue happy endings.
Rose, for example, says she was saved by one of her clients, Claudio. Now he's her partner and together they have written a book about their story, hoping to raise awareness about the problem of Nigerian immigrant girls on the streets of Italy.