Author and illustrator Daria Peoples opens this book with a dedication to her parents: "Thank you for showing me how to see and know and love my neighbor." She then offers this same gift to her readers by having her narrator, a young girl on an outing with her papa, introduce us to Mister Blue.

Mister Blue and her papa go way back to days in the army together, which we learn through flashback pictures. The girl tells us:

They went through some weary days
and some looking-up days
and some just-gotta-keep-pushing days.

Through it all, Mister Blue has given of his gift of music, "a too-good-not-to-move-groove" played on guitar, trumpet, harmonica, and drums. So when the girl and her father visit him, they join others in the street to rise, march, and boogie! We see people holding signs for Black Lives Matter, Say Their Names, Love Not War, and Resist, through which the musical notes of Mister Blue's drumming magic float.

Our young narrator, knowing that Mr. Blue doesn't have a house and keeps his possessions in a shopping cart, has lots of questions: "Is he safe? Is he scared? Is he lonely?" These questions and more go with a series of pictures showing a dark, drenching downpour that gathers strength as she and her father head home. While we won't give away the story's ending, perhaps you can imagine — given her concerned questions — why she takes her father's hand and starts heading back toward where they left Mister Blue.

The depth of hospitality and friendship in this story is an astonishing bolt of clear insight about what matters, framed within 32 pages for children ages four to eight. At the end, the author recalls hearing that there are those who choose to see and those who don't. She adds:

I believe children choose to look, to see, to contemplate, and to act by asking hard questions we adults don't always know how to answer.

It's important that we don't prevent children from asking hard questions.

It's important that we don't prevent ourselves as adults, either. That is what makes Hello, Mister Blue, compelling for all of us.