Congratulations! I’m Prefect Gemma Farley, and I’m delighted to welcome u to SLYTHERIN HOUSE. Our emblem is the serpent, the wisest of creatures; our house colours are smaragd, emerald green and silver, and our common room lies behind a concealed entrance down in the dungeons. As you’ll see, its windows look out into the depths of the Hogwarts lake. We often see the giant squid swooshing door – and sometimes meer interesting creatures. We like to feel that our hangout has the aura of a mysterious, underwater shipwreck.

Now, there are a few things u should know about Slytherin – and a few...