Nairobi, Kenya - Ducking beneath the tin roofs of rickety houses and past streams of raw sewage, a member of Kenya's outlawed Mungiki sect acts as an angry tour guide to the sprawling slum of Mlango Kubwa.
A world away from the pristine office blocks of downtown Nairobi, just a few miles from here, it is a breeding ground for disease and resentment against the poverty-stricken nation's ruling class.
"The Mungiki sect will clear all this up soon," says the guide, who identified himself only as "Peter" for fear of arrest. "We must take pride in ourselves - that's what our grandfathers in Mau Mau taught us."
Half a century on from their bloody revolt against British colonial rule, the spirit that fired the Mau Mau is back - only this time its violence is directed not against white rule, but the black rule that replaced it.
Preaching a return to tribal ethics, the Mungiki - whose followers describe themselves as "the true sons of the Mau Mau" - are viewed as little more than a vicious street mafia by the Kenyan government, which points to their track record of murders, rapes and racketeering.
But their standing in their ghetto strongholds has risen in the wake of a huge corruption scandal that has rocked the administration of President Mwai Kibaki in recent weeks.
Documents disclosed last month by the country's former anti-corruption chief, John Githongo, now in exile in Britain, have linked senior government figures to a series of suspect contracts designed to loot £150 million from state funds.
Public anger has been further inflamed by disclosures that apparatchiks have spent more than £7 million on fleets of new luxury cars since 2002 - money that could have helped the four million Kenyans needing food aid.
Peter is among up to 400,000 mainly unemployed Kenyans who have joined the sect in recent years. Born and raised in the slums, he believes that the cure for his country's many woes is eschewing "degenerate" aspects of Western culture and embracing a simple, pre-colonial life.
"You must be pure and live cleanly like our ancestors," he told the Sunday Telegraph.
"We are doing bad things: we have girls in prostitution, a government taking money from its own people and we have forgotten our past. God is sending drought to punish us."
Like the Mau Mau, the Mungiki is drawn from Kenya's majority Kikuyu tribe, whose uprising in 1952 over the appropriation of their farming lands saw them kill white settlers.
Although only 32 were murdered, the manner of the killings horrified Britain - a child on a tricycle was beheaded, while other victims were hacked to pieces with machetes. In reprisals by British forces, 1,048 Mau Mau were hanged. The four-year battle to stamp out the insurgency ultimately cost around 11,000 African lives.
Today, the Mungiki advocate a return to traditional customs - abstaining from alcohol, facing Mount Kenya to pray, and sniffing tobacco as their holy communion. The only difference is that to avoid arrest, they tend not to wear the Mau Mau's distinctive dreadlocks.
In the Mlango Kubwa slum, where most residents get by on less than £1 a day, clan members make monthly collections in return for promises of security and keeping the streets clean.
In its quest to save Kenya from Western decadence, however, the group has also embraced much-reviled practices - such as stripping women of miniskirts and trousers in public and forcibly circumcising them.
Only last week, British High Court judges overturned a Home Office ruling to send back a 31-year-old women who had fled Kenya after being raped by the sect, upholding her claim that she could be circumcised if she returned.
Many commentators say the group's ideological claims are just a smokescreen to mask its illegal activities, which include running protection rackets on private minibus routes.
One owner, who did not wish to be named, said it cost him more than £100 a day in bribes to keep his fleet of minibuses safe from Mungiki gangs armed with machetes and clubs.
He said: "My workers have been beaten up and we've had our windows smashed. It's domestic terrorism, but it's better to pay and keep safe."
Public resentment at the extortion activities of the sect boiled over recently when five members were lynched by an angry mob in the Maragwa district north of Nairobi.
Last week, Kenyan police, acting on complaints from bus travellers, arrested more than 250 suspected Mungiki members after a four-hour operation in the capital's slums.
On Thursday the leader of the group, Maina Njenga, was also detained, following a declaration of "all-out war" on the sect by Kenya's security forces.
Father Joachim Omollo Ouko, a political commentator who has followed the group for the past five years, said: "The young men who are joining are just poor slum kids who can't find jobs.
"It may be that they are attracted by a certain ideology, but if this group really believed what they preach they wouldn't go around robbing and stealing from people."