The book was later adapted into a 1985 film starring Emilio Estevez and Craig Sheffer.

The two often spend time hanging out at the local bar and playing pool to earn money, along with a strange boy named M&M.

The pair attend a dance together, where Mark and Ponyboy Curtis get in a fight with a boy who Bryon’s ex-girlfriend, Angela, told to beat the two up.

Cathy resists, but Bryon assures her it is fine and they drive away, in hopes of coming back for him.

He comes to the conclusion that Mark is selling the drugs in order to make money.

However, unlike Rumble Fish, Ponyboy Curtis, the main character in The Outsiders, appears in That Was Then, This Is Now and even takes part in the events surrounding the dance.

The characters of Tim and Curly Shepard from The Outsiders also appear, as does their sister Angela, who is original to That Was Then, This Is Now.

Mark later appears as a hitchhiker, who has recently escaped from prison and killed multiple people.

He forces Tex and Mason to drive him to the state line, holding them at gunpoint; he is killed soon after by the police.

When he asks her, Cathy says that they weren't exactly friends, but she knew him for a long time and they shared a past.