She calculates probabilities. He throws punches. The only variable they didn't account for was falling in love.
Dr. Olivia Moore has a hypothesis: Life is safer when you control the variables. As a biochemist, she thrives on data and logic. But when she finds her boyfriend cheating with her roommate, her carefully curated life implodes. Homeless and heartbroken, she posts a desperate ad for a roommate. She expects a student.
She gets Claude Russo.
A 240-pound underground boxer with scarred knuckles, eyes like ice, and a past he's running from. He's massive, dangerous, and completely occupies her small Queens apartment-and her thoughts.
They agree on ground rules. No questions. No personal entanglements. Just a business transaction.
But when Olivia's toxic ex refuses to let go, Claude steps out of the shadows. Suddenly, the grumpy giant who eats all her eggs becomes her fake fianc , her protector, and the only man who makes her feel safe.
From a shared tiny bathroom to a "one bed" situation that tests every boundary, the tension between them becomes explosive. Olivia knows Claude is hiding a deadly secret that could destroy them both. But as his walls come down, she realizes the most dangerous thing isn't the mob chasing him-it's the risk of giving her heart to a man who might leave to save her.
"I would burn the world for you, Plankton."
The Protection Variable is a steamy, swoon-worthy Grumpy x Sunshine romance featuring a STEMinist heroine, a protective boxer hero, and the forced proximity trope that will make you melt. No cheating, and a hard-fought HEA guaranteed.