Correspondence

This was not the summer that it all began. This was the summer that it all ended.

Addison Larson is a normal girl. She has a mother, father, and brother. She goes to school. She likes music. Unlike a normal girl, Addison Larson lives on a top secret military base on an island near the coast of Northern Africa. Her little brother -- "her whole world" -- has cancer. Her father, who still hasn't quit smoking, divorced her mother only months ago.
On her sixteenth summer, Addison's mother decides to send Addison to an on-base community center to distract her. There, she is forced into a pen pal program by the boisterous Head Advisor.
Enter Evan Quin, son of a highly ranked Officer. He, too, lives on a top secret base; only, this one is in the heart of London. His family is orderly: perfect older sister, obedient older brother, stay-at-home mother, and ladder-climbing father. Nothing in his life is wrong. Except his social anxiety.
The two strangers quickly latch on to each other, treating the other like a human diary. Until the day Evan writes the simple clause, "I'm moving."