Like his son and his grandson, Grandfather's name is Alex. Beside the name, though, these three stooges don't seem to have much in common.
Well… we take that back. Anger does kind of run in the family. Although Grandfather "has never violenced [Alex] or Little Igor" (5.7), he gets pretty angry at Alex for screwing up the navigation, laying out the ol' "I gave you one thing to do and you screwed it up!" speech, which Alex later gives to Jonathan when Jonathan talks to someone, in English, about Augustine. (Confused yet?)
Anyway, the point is, at one point Alex yells at Jonathan, "I asked you to do one thing, and you made a disaster of it! You were so stupid!" (15.17). See? Looks like names aren't the only things that run in families.
Aside from the occasional anger management issues, Grandfather is pretty mellow—if you can ignore the quirks, like how he thinks he's blind and needs to be led around by his seeing-eye bitch Sammy Davis Junior, Junior even though he's the designated driver on the journey to take Jonathan Safran Foer to Lutsk, or how he often falls asleep at the wheel. (Don't worry, they're always parked when he conks out.) Here's the really quirky thing: when he wakes up, he always calls out his dead wife's name, Anna.
Ah-ha! Character insight. Grandfather isn't really blind; he's actually lonely after the death of his wife. Alex's dad tells Alex not to mention her, because "it will make [Grandfather] more melancholy, Alex, and it will make him think he is more blind" (1.11). It's almost as though the loneliness makes him not want to see. But let's ask you this: what is he shutting his eyes to avoid looking at?
Maybe we should take a closer look at what he did during the war.
Grandfather becomes obsessed with finding Augustine before Alex does, and almost seems more determined to find the woman than Jonathan: "We should try very inflexibly to help him," he says to Alex: "I would like very much to find Augustine" (10.29). (By this point, we're pretty set on finding her, too.)
Things get weird when Grandfather meets the woman they think is Augustine but isn't. He goes from saying, "You are very beautiful" (18.6) to, when he finds out that she isn't Augustine, insisting, "You should have died with the others" (18.15).
Whoa. What's up the mood swing, gramps?
Look at it this way: Augustine might as well be a code word for "the past" because Grandfather is ultimately less concerned about Augustine and more concerned with fixing past mistakes, which he thinks Augustine represents. When Augustine-who-isn't gives them a photo of Grandfather and his friend Herschel, that's when the whole tragic tale unravels. Fast. In Grandfather's words: "[Herschel] was my best friend. […] And I murdered him" (26.56, 26.58).
Here's the long story:
The Nazis came goose-stepping into town, lined everyone up, and asked who the Jews were. Grandfather pointed at Herschel to save himself and his family, and Herschel died. Grandfather, obviously, has never forgiven himself. After all, they were best friends. Grandfather sadly remembers the moment before Herschel's death: "I saw Herschel and he saw me and we stood next to each other because that is what friends do in the presence of evil or love" (29.86).
Man, where are the tissues? We need a whole box.
Since this isn't a sci-fi novel or The Terminator, Grandfather can't change the past. Even though he asks Alex for money, Alex knows that Grandfather doesn't really want to find Augustine, and what he really wants can never be accomplished.
However, Alex does forgive him. He says, "Grandfather is not a bad person, Jonathan. Everyone performs bad actions. I do. Father does. Even you do. A bad person is someone who does not lament his bad actions"(17.11). And grandfather practically does nothing but lament his actions. He spends all his time after the trip crying and crying—and in the end, he kills himself, telling Jonathan in his final letter that his suicide is not because he "cannot endure" but because he is "complete with happiness" and ready to "open the door into darkness" (34.23).
Perhaps after death, everything will be illuminated for Grandfather.