15-year old David Okot seemed angry, and he had every right to be.
I couldn't tell whether his incomprehensible babbling was directed at us, his family, or himself. He wore nothing but a black turtleneck that matched his mood.
Perhaps in a show of defiance David had discarded his shorts, leaving him naked from the waist down. At his feet was perhaps the source of his distress. A thick, frayed rope that was tied tightly around his ankle. It snaked along the ground and into the small thatched hut that was his home.
He had wandered off a few times, hence the need to hold him captive, explained his mother. Villagers were somewhat afraid of him, concerned that David might throw stones or cause harm in some other way.
But the crux of the problem was that David suffered from a mysterious condition that preys only on children. It has no official name, but is known informally as "nodding disease."
Experts from the World Health Organization, the Centers for Disease Control and Prevention (CDC) and the Ugandan Ministry of Health have concluded that it's a brain disease, but they can't determine the cause and there's no effective treatment.
A recent study identified nearly 2,000 children with the condition in three districts of northern Uganda. Others are affected in neighboring Sudan.
In David's village, almost every family has at least one child with the disease. The first symptom is an involuntary nodding of the head and brief losses of consciousness, as if the child is falling asleep. Over time they often begin to have seizures, experience stunted growth and develop mental retardation.
The children usually have to drop out of school and are unable to work, becoming a burden to their families who already live in the most challenging of conditions.
Their parents are distraught because there's no telling whom it will strike next. Nodding disease seems to be indiscriminate.
Some of the brightest minds in medicine have been tying themselves in knots trying to determine the cause. "I wish we knew," says the CDC's Scott Dowell. "It's really frustrating."
One theory, which is being studied at Makerere University in Uganda's capital, Kampala, is that nodding disease could be linked to psycho-trauma.
Villagers from the affected area in northern Uganda have certainly experienced more than their fair share of traumatic events. The region is the former home and stronghold of Joseph Kony and his brutal guerrilla group the Lord's Resistance Army (LRA).
Thousands of people there were displaced by the rebels, who've been accused of systematic murder, rape and kidnapping of children over the last 25 years. The LRA has since been driven away, but the scars remain.
Studying eight children with nodding disease, the Makerere researchers have found reason to believe that the children could be suffering from something similar to post-traumatic stress disorder. However, the study is far too small to be considered significant.
Officials from the CDC and the World Health Organization have told us that more research is needed, but it's unclear whether the resources will be forthcoming.
As for their research, the scientists are essentially feeling their way in the dark, hoping to hit on something that will lead them in the right direction.
David Okot and others like him also remain in the dark, but the difference for them is that the prevailing sentiment is fear, confusion and yes, anger.
David Lindsay is the Managing Editor of Global Health Frontline News. David, videographer Rhett Turner and sound tech Greg Pope, went to northern Uganda to report on nodding disease.