There are a couple of signs in this weeks' chapters that show Henry well on his way to being in love...

At the assembly rooms dance "Catherine ... enjoyed her usual happiness with Henry Tilney, listening with sparkling eyes to everything he said; and, in finding him irresistible, becoming so herself."

Henry talking to Catherine about Frederick's motives "...your attributing my brother's wish of dancing with Miss Thorpe to good nature alone convinced me of your being superior in good nature yourself to all the rest of the world."