Before now, Kemp's neighbor, Heelas, didn't believe in the Invisible Man. But when he wakes up from a nap and sees Kemp's house broken into and Kemp running toward him, Heelas does the only sensible thing: he locks himself inside his house and refuses to help his neighbor.
From Heelas's point-of-view, we see Kemp run through the garden followed closely by the Invisible Man. (Or the traces left by the IM, at least.)
Kemp continues running towards Burdock (just like Marvel did in Chapter 15). It sounds something like a nightmare: the road is long and empty, and no one in the nearby houses will help him.
Still, when Kemp arrives in Burdock, he finds a couple of workmen (navvies) on the road. When he yells about the Invisible Man, everyone nearby tries to find and hit the IM – shovels and all.
When the Invisible Man grabs Kemp, the navvies knock the Invisible Man down. So maybe these guys are the real heroes of the book?
The narrator notes that the next scene might have looked like a game of rugby, but it was actually a big fight between the crowd and the Invisible Man.
Spoiler alert: the Invisible Man loses. "There was, I am afraid, some savage kicking. Then suddenly a wild scream of 'Mercy! Mercy!' that died down swiftly to a sound like choking" (28.17).
Kemp tries to get people off of Griffin, but the IM is already not breathing and possibly dead.
Everyone crowds around to see what happened, and slowly, the Invisible Man starts to become visible (but still naked):
And so, slowly, beginning at his hands and feet and creeping along his limbs to the vital centres of his body, that strange change continued. It was like the slow spreading of a poison. First came the little white nerves, a hazy grey sketch of a limb, then the glassy bones and intricate arteries, then the flesh and skin, first a faint fogginess, and then growing rapidly dense and opaque. Presently they could see his crushed chest and his shoulders, and the dim outline of his drawn and battered features. (28.27)
That's how Griffin's experiment in invisibility ends, with people covering up his "naked and pitiful" body (28.28).