In our series of letters from African journalists, novelist and writer Adaobi Tricia Nwaubani profiles the lawyer who brokered the release of 82 women captured by Nigeria's militant Islamist group Boko Haram.
When 57-year-old Zannah Mustapha arrived for the handover of the 82 Chibok girls freed from Boko Haram after three years in captivity, a militant read out the girls' names from a list.
One by one, the abducted schoolgirls, now women, lined up along the outskirts of a forest near Kumshe town, on the border between Nigeria and Cameroon. Each of them was covered from head to ankle in a dark-coloured hijab.
"I went ahead of the Red Cross. They [the militants] brought the girls to me," said Mr Mustapha, the lawyer from Borno state in north-east Nigeria.
He has been mediating between the government and militants for the release of the Chibok girls and for an end to the Boko Haram insurgency.
In 2015, President Muhammadu Buhari told the media that his government was willing to negotiate with "credible" leaders of Boko Haram for the release of the girls.
More than 200 of them were abducted a year earlier from the north-eastern town of Chibok, sparking global outrage.
Previous attempts had failed, with different groups coming forward, each claiming to be the militants in possession of the missing schoolgirls.
It was Mr Mustapha who succeeded in convincing the Nigerian authorities that this particular group should be taken for what they say, presidential spokesman Garba Shehu told me.
"He had dealt with them in the past and they keep to their word," he said.
Mr Mustapha's role as a mediator dates back to his founding the Future Prowess Islamic Foundation School in 2007, to provide free Islamic-based education to orphans and the poor.
When the Boko Haram insurgency erupted in 2009, the school offered admission to the children of soldiers and government officials killed by the militants, as well as those of militants killed by the state.
Mr Mustapha then sought the assistance of the International Committee of the Red Cross (ICRC), which began providing free meals to the pupils.
He also encouraged parents to form an association which would reach out to other widows and convince them to send their children to his school.
The ICRC soon extended its humanitarian services to the mothers, providing them free food and other items every month.
"This was at a time when the wives of Boko Haram militants were being arrested and their houses demolished, so Boko Haram saw me and the ICRC as neutral parties," Mr Mustapha said.