Near the start of Let the Circle Be Unbroken, an all-white jury sentences T.J. Avery to death for the assault of a white shopkeeper, despite good evidence of his innocence. For days after reading this, food tasted bland to me, games seemed less fun. Eventually, hopefully, I asked my mother, "But our country's not really like that, right? It's just a story." Ever an honest woman, that mother of mine, she told me no. She was afraid it had been just like this and in certain ways still was. I remember thinking that this was basically it for me as far as ever enjoying life again. This was not a world I wanted to enjoy.

Of course I bounced back quickly. It was easy to fall into forgetting that the world was not as happy and seemingly fair for everyone as it was for me. There were Barbies waiting to star in religious dramas of my own devising; there were other, cheerier books waiting to be read. But Cassie remained an important part of my mental landscape, as so many well-drawn characters have. I tend to think about her a lot this time of year.

That's because every MLK Day I go through a quicker, less harrowing version of that cycle of fury and forgetting that I went through as a 9-year-old. I read powerful words — some King's, some not — and I recommit myself to ferreting out my biases, to fully acknowledging my unearned privilege, to seeking ways to work for social justice. This happens at other times too — as it did in the wake of the Trayvon Martin verdict, and as it does when another new study reveals disproportionate rates of black incarceration. But always these bursts of commitment are shorter-lived than one might hope. Days or weeks later I forget how much of what I enjoy — and what so many people take as their due — is available to me for no better reason than that I'm white.

I forget because I am as lazy, selfish, and frightened as the next person. Because, like so many of us, I am just trying to get by, to hold on to what I have, maybe get myself a little more, and it is easy for me to fall into believing that if only I can get that little more I'm reaching for, I can relax a bit, and then, finally, I can turn myself toward noticing how much of what I have others lack. There are many things that spur me to try harder whenever I fall into this way of thinking. One of those is a fictional little girl who has lived in my head for nearly 30 years. Because I knew her. Because I loved her. Because, for the hours I spent reading those books, it felt as though I was her.

A few months ago there was a lot of media chatter about a study by psychologists David Comer Kidd and Emanuele Castano suggesting that reading literary fiction improves our capacity to detect and decipher other people's emotions. Of course there's a sizable leap between detecting and caring, as any manipulative psychopath can tell you. But anyone who has ever loved a character like Cassie knows that good novels can make you do both, that your happiness can become tied, enduringly, to the happiness of characters just like you or to characters very different from you, be that in race, class, temperament, age, or along any other dimension. That, as George Eliot put it, "when Wordsworth sings to us the reverie of 'Poor Susan' ... more is done toward linking the higher classes with the lower, toward obliterating the vulgarity of exclusiveness, than by hundreds of sermons or philosophical dissertations."

This is certainly not the day to knock sermons or philosophical dissertations. King brought both forms to their highest moral and aesthetic reaches. But novels, or rather the characters who populate them, can stay vivid in our minds far longer than even the most compelling rhetoric. In the interest of sustaining our hunger for social justice in the days and weeks ahead, when the sermons and philosophical dissertations are no longer popping up on every corner of the internet to keep us honest, maybe the best way to celebrate King's legacy is to pick up a piece of fiction.

Here are 18 that set about "obliterating the vulgarity of exclusiveness" in particularly spectacular fashion.