Both the Grandfather (Thomas Schell Sr.) and the Grandmother (unnamed) survived the Dresden bombing as teenagers, though everyone else in Grandmother's family died. Among the deceased was Grandmother’s older sister, Anna, who was in a relationship with Grandmother's now-husband Thomas and was to have their child. Both Grandmother and Thomas Schell Sr. fled to New York after the bombing of Dresden but were not aware of each others locations following the attack. While in New York, however, Thomas loses his ability to speak and has to write out his thoughts inside of a notebook. He even has “No” tattooed on his right hand and “Yes” on his left in order to speed up his ability to answer questions. Months later, Thomas and grandmother meet by chance again and reconnect at a rapid speed after they make love and he molds a sculpture her body out of clay. After moving in together and marrying, they started distancing from each other. When living together, the couple has “nothing” spaces laid out around their home where they could both ignore each other and anything else around them, and "something spaces" where their relationship was valid and where they could enjoy the company of each other. This issue started becoming exacerbated when more and more of the house became “nothing” instead of “something” (a metaphor for how their relationship was slowing becoming nothing). Soon after, Grandmother becomes pregnant, which causes Thomas to leave. He left because of his inability to commit to having a child, but also because of his inability to communicate with his son. This abandonment leaves Grandmother heartbroken, but many years later, Thomas comes back. She makes him promise to keep his arrival and presence a secret from Oskar and Oskar’s mother and she refers of him as "the renter" whenever anyone asks. He breaks this promise when Oskar comes over and sees Thomas for the first time, mistaking him for "the renter”. They soon grow a quick bond and the story then continues as Oskar tries to find the lock to the key with his grandfather by his side. Thomas Schell Sr.'s and Grandmother's narrations in the story is told through the letters that they write, addressed to Oskar and their "Unborn Child" (which is a reference to Oskar's father, Thomas Schell Jr.). Towards the end of the story, Oskar’s grandmother and Thomas move to the airport together, abandoning Oskar who by this time has already secured his bond with his mother.
Sources:
Foer, Jonathan Safran. Extremely Loud and Incredibly Close. Boston, MA: Mariner, 2005. Print.
Foer, Jonathan Safran. Extremely Loud and Incredibly Close. Boston, MA: Mariner, 2005. Print.