A casual observer might consider the occupants of the silver Toyota Land Cruiser a strange assembly: two smart young men in front, the passenger dreadlocked; a gaunt, ashen Maasai and an elderly white man in the back seat, and, hunched on the jump seat in the rear, looking out through the glass, a ragged street boy taking his first ever ride in a car.
But there are no casual observers on the street tonight: no disinterested parties, no innocent bystanders.
They pass groups of men - and some boys - headed, it seems for Uhuru Park. They walk purposefully, lithe limbs swinging. And something - sticks, or clubs, or pangas - bouncing at their sides.