Bored one day in high school physics, author David Levithan began to write a short story about love, using the concepts and vocabulary he was learning in class (“She feared fusion would only bring fission, with the mass deficits too great and the energy spent too time-consuming to make the romantic endeavor worthwhile.”). It became a Valentine’s Day gift for his high school friends and the start of an annual tradition that he has continued to this day. Many of the eighteen short stories in this collection are from his Valentine’s Day offerings, including “A Romantic Inclination,” the physics class story he wrote at age sixteen; “Memory Dance,” written a year later; and “the escalator, a love story,” written when he was in college. Five stories in How They Met have been previously published in other collections; others are original to this volume. Each story deals with romantic love, particularly the giddy sort that defines so much of adolescence. Half of the stories feature gay main characters falling in and out of love, and Levithan excels at these. His well-rounded characters are shown with depth and humor, and when their families are added to the mix, as they are in “Princes” and “What a Song Can Do,” the result is nothing short of brilliant. Whether the characters are straight or gay, all of the stories are ultimately about the same things: What attracts one person to another? What miracle of chance brought them together? And, as the author first mused as a sixteen-year-old in a high school physics class: “After the initial impulse, would the momentum remain constant?” (Age 14 and older)