I have a grandson your age.

In his initial investigation into the murder of the dog Wellington, Christopher goes around methodically knocking on his neighbors’ doors asking them questions about the murder. When he gets to Mrs. Alexander’s door, she greets him with warmth and friendliness, the first neighbor to do so. The elderly Mrs. Alexander then invites him in for biscuits, but Christopher refuses since she is technically a stranger. However, she tries to establish trust with him by telling him she has a grandson his age.

Christopher, please, just trust me.

When Mrs. Alexander realizes that Christopher isn’t aware his mother isn’t really dead, she decides to tell him the truth. In a key moment, Mrs. Alexander asks Christopher to trust her, something he normally will not do with a stranger. Mrs. Alexander forges a bond with Christopher by revealing two very powerful and painful truths: His mother is not dead, and she was having an affair with Mr. Shears.

I’m not a stranger, Christopher, I’m a friend.

Mrs. Alexander points this fact out to Christopher in an attempt to help him trust her. On Christopher’s road to independence, his relationship with Mrs. Alexander provides him with an opportunity to learn how strangers can turn into friends. Christopher fears strangers and keeps a safe distance from them to protect himself. He knows he can’t navigate social interactions well, which makes “stranger danger” even more acute for him. But Mrs. Alexander’s persistent attempts to reach out give him the opportunity to develop a nuanced perception and discern safe strangers from dangerous strangers.