Severus scowled at the barn owl, recognizing the letter's handwriting.
"What's it say?!" A skill beyond either of the Carrows.
"...it's about Potions," he drawled (lied).
The Carrows' didn't believe him, snatching the letter to read for themselves. Severus let them, he already knew what it said;
Mix Thallium and Ethylene Oxide, add in crushed Iodine and Sulfur and then pour into the Oxygenated Tungsten Levo cauldron.
More importantly, he knew what it meant.
ThEO IS OWl
"Wait in my quarters for me to pen a reply."
The Owl-Nott-nodded and flew away.
Severus sighed.