Jacob, now fifteen, gets a call at the pharmacy where he works; it's Grandpa, and he's frantically searching for the key to his gun cabinet.
He says, "It's not safe" (1.27), and he needs the guns to protect himself.
Jacob's dad has taken the key because he doesn't think it's safe for his senile old man to have access to tons of firearms.
Jacob calls his dad, and his dad asks him to go check on Grandpa.
Jacob gets a ride from his friend Ricky and the two of them rattle over to Grandpa's neighborhood in Ricky's rickety car.
On the way there, they pass a creepy old man watering his lawn: "His eyes were a perfect milky white" (1.61). Jacob wonders why Grandpa never told him that one of his neighbors is blind. Um… why would he mention that? It's not like he's a serial killer or a child molester.
The boys enter Grandpa's house and find the place a total wreck.
Jacob notices a gleam of light from the backyard, and he finds Grandpa's flashlight abandoned in the grass.
He decides to search the woods which, "according to local legend, [are] crawling with snakes, raccoons, and wild boars" (1.74). In other words, they're like every single forest everywhere.
After tracking Grandpa through the forest (no raccoons in sight), Jacob finds him with his shirt clawed open and bloody.
With his dying breaths, Grandpa tells Jacob to "go to the island" (1.89) and "find the bird. In the loop" (1.95), as well as stuff about Emerson and September 3, 1940. He's either going crazy or he was watching Lost before whatever just happened to him.
Grandpa dies in Jacob's arms, and Jacob realizes something in the woods is watching them. And it ain't a chipmunk.
It's a creepy tentacle-mouthed creature.
Ricky shows up just in time and fires his gun in the general direction of the creature, even though he doesn't see it.