To many people M23 is a motorway but to anyone with a passing interest in Eastern Congo it's the latest headlining rebel group. M29 is Alphonso's version, but he seems unaware of the parody. "We are the movement for defending the rights of minorities", Alphonso says, holding up the bomber jacket to display the logo proudly.
This elderly man is the tragic embodiment of 20 years of intermittent conflict in Eastern Congo. 50% of adults here meet criteria for post-traumatic stress disorder, according to a painstaking population-based 2010 survey of the east. That's more than 3 million adults. The same study found that over a million adults had attempted suicide in the last year.
Young men and women whose minds fail to cope with the violence and continual displacement - "les fous" - get bound up like turkeys and kept in a dark room. They arrive at the mental health clinic with their wrists bleeding from the metal fetters they've lived with for months, sometimes years. They are the lucky ones. Others are left behind in villages when rebels arrive, only for the rebels to shoot them dead, or worse.
Alphonso's only crime is that he's mad, the tour guide says. But he has no family and lives in a place with almost no capacity to deal with mental illness so he's in prison. He sleeps alongside three other men on a lower bunk-bed. The room is just fifteen paces long but sleeps over a hundred men - fourteen bunks, eight to a bed. Some sleep in shifts. The prison was designed for 150 in total but houses 536 at the moment.
Four men are "properly mad" in Goma prison, according to inmates. Aside from over-crowding their main complaint is that everyone is lumped in together, the mentally ill, national army veterans, M23 rebels, Mai Mai militiamen, petty criminals, and some who have never even seen a charge sheet. They eat the same thing, rice and beans, every day. "On va mourir" [we're going to die], one man says.