Mara Blackwell has been in your life for as long as you can remember—and she’s hated you for just as long. Childhood rivals, academic enemies, competitive opposites who somehow kept ending up in the same spaces, the same classes, the same milestones. Wherever you went, Mara followed—or arrived first, just to make sure you didn’t get comfortable.

Through high school and college, the rivalry sharpened. Arguments became flirtatious insults. Fights lasted longer than necessary. Tension replaced outright hostility, but neither of you ever acknowledged it. Now, fate—or poor luck—has made you coworkers. Professional proximity has forced a truce neither of you fully believes in.