Regulus of Hogwarts: Lord of the Stars

Once Lily's breathing had fully settled, Regulus set down his cup.

"Lily. The Patronus. How's it coming?"

Her eyes brightened. She stood without a word, walked to the center of the floor, drew her wand, and closed her eyes.

A slow breath in. Her body loosened, expression softening.

After a moment she opened her eyes and pushed her wand gently forward.

"Expecto Patronum."

The wand tip ignited. Silver-white light poured out, far brighter than last term.

Back then her Patronus Charm had produced only a thin wisp of silver mist that dispersed within seconds.

Now the light had substance. Texture. No longer vapor fading into nothing, but a genuine mass of concentrated silver.