There is a telling anecdote in the epilogue of Ngozi Okonjo-Iweala's account of her second stint presiding over the mercurial finances of Africa's largest economy. After she had left Nigeria and office, police acting on the tip of a supposed whistleblower raided her house in Abuja in search of cash hoards. When they found some bags in the basement, they thought they had hit the jackpot. Only the bags turned out to contain four years' worth of newspaper clippings. No money.
One of the most insidious tactics deployed by vested interests against those obstructing corruption is to spread malicious rumours that cast doubts on the integrity of their target. Long before US president Donald Trump had popularised the terms "fake news" and "alternative facts", Nigeria's gangster politicians and profiteers had honed that dark art.
Mrs Okonjo-Iweala, a former managing director of the World Bank who paved the way for the writedown of Nigeria's historic debts as finance minister between 2003 and 2006 -- and served again under the hapless administration of Goodluck Jonathan between 2011 and 2015 -- has been relentlessly targeted: a sure sign that she trod on powerful toes.
Her second book is partly a bid to set the record straight in the wake of venomous allegations that trailed her out of office when Mr Jonathan lost elections in 2015 and the government changed hands. It is also a courageous account of the battle against graft in Nigeria. Between the lines, the book also serves as a diagnosis of what is wrong and a prescription for how it could be put right.
There are tragicomic moments. One is when Mrs Okonjo-Iweala puts paid to a duplicate cargo tracking system at the ports tailored to line pockets. This act rebounds on her when she finds she can no longer enter the president's residence via the VIP entrances. Even in the company of the visiting IMF chief, Christine Lagarde, she is forced to make detours through the gardens.
Often, the counter-attacks were far more sinister. Mrs Okonjo-Iweala's 83-year-old mother was kidnapped and bound for days at the suspected behest of oil marketers, whose fraudulent subsidy claims the minister had blocked. Their ransom demand was that she resign on television. She did not. Soon after, she was warned of a plot to attack her personally. She recalls one meeting that the president asked her to attend with a group of businessmen from Abu Dhabi, who promised $2bn in loans dressed up as an investment in ship building.
"The presidential adviser had the I-told-you-so look, as though once you get this woman involved, then this won't work." The adviser was right. She blocked what looked to her like an attempt to replicate a 2013 fiasco that had seen the state of Mozambique saddled with hundreds of millions of dollars of odious debt in return for a redundant tuna fishing fleet.
The book may be a self-defence, but it is not self-congratulatory. Much of it describes the relentless task reformers take on when they seek to plug the leaks springing from the state. There are ghost workers and pension scams, collusion between contractors and civil servants in bogus debt, and near constant arm wrestling with legislators and state governors to prevent waste.
All the time, income to the Treasury, most of which comes from oil, was being squeezed -- on one side, by industrial scale theft from pipelines and state company accounts; on the other, by multibillion-dollar fraud in the allocation of fuel subsidies.
As a result, one of the world's foremost development experts spent most of her time mounting rearguard actions to prevent Africa's leading crude producer going bankrupt in an oil boom. "The government's stance against corruption delivered mixed messages," she writes with considerable understatement.
Friends warned her not to work for Mr Jonathan, fearing she would lend credibility to a government that did not merit it and sacrifice her own hard-won reputation. She still has her own misgivings, mostly about the dangers faced by her family.
Nevertheless she believes it was worth it. Billions went missing. But by her own estimation, finance ministry interventions saved the country around $9bn directly. As another Nigerian reformer put it to me once: "Had she not been there, it would have been much, much worse."