Jeremy Simms is blond with blue eyes. He walks with the Logan kids to and from the crossroads every day, even though he's apparently punished for spending time with them. He's kind and shy; he takes up for Cassie in front of Lillian Jean and his father. He likes the Logan family even though the rest of his family is prejudiced and racist. Even Stacey thinks he might be a better friend than T.J. to him.

T.J. Avery is 14. He's reckless and can be cruel. He's confident and willing to spend time with other cruel people like the Simms brothers, commit crimes, and create havoc. He's more daring than Jeremy. He's louder and more opinionated. Unlike Jeremy, T.J. doesn't like people of the opposite race. For example, he tells Stacey that he wouldn't keep a whistle that a white boy blew on. However, this is likely the result of the prejudice against T.J. because of his skin color. T.J. takes advantage of his younger brother by claiming that Claude, not T.J., snuck out, so that their mother will punish Claude instead.

Both boys are friends with the Logan family. Both boys come from relatively poor families without a lot of opportunities. Both are young and have parents that use physical punishment.

While Jeremy Simms and T.J. Avery are both friends of the Logans, Jeremy risks much more in this friendship than does T. J., who like the homonym of his name, aviary, takes flight from difficult situations.  Jeremy, the brother of Lillian Jean who is so cruel to Cassie Logan, intrepidly risks castigation from the other white children and punishment by his father, Charlie Simms by walking with the children to school and by bringing to the house Christmas presents for the Logans.  On the other hand, the disloyal T. J. does not stand by the Logans during any of the racial crises.  He is underhanded, as well.  For instance, he tells the kind-hearted Christopher-John that the coat which Uncle Hammer has given him is too big for the boy, and, Christoper-John tells his mother,

"...T. J. said it made me look like a preacher...and he said since it fit him just right, he'd....take it off my hands till I grow into it,, then thataway all the guys would stop laughing at me and calling me preacher."

In his most egregious act of disloyalty, a disgruntled T. J. reports Mrs. Logan for having begun the boycott of the Wallace store because she has failed him.  This traitorous act causes Mrs. Logan her teaching position. 

Certainly, Jeremy Simms and T. J. Avery are the antithesis of each other as Jeremy is a character who represents compassion and unselfish friendship--although he does run after his sister Lillian Jean when Cassie retaliates against her--while T.J. is self-serving and uncaring of others.