Slave Pen

This is where the party find themselves at the start of the adventure, having being captured by the drow for sale.
The characters begin the adventure in the slave pens of Velkynvelve. Stripped of everything but their underclothing, they are at the mercy of the dark elves and in the company of other prisoners, many of who aren’t what they seem.
All the drow’s prisoners, including the characters, wear iron slave collars along with manacles connected to iron belts by a short length of chain. This leaves the prisoners restrained, but doesn’t affect their movement or speed.
Velkynvelve’s slave pen is closed with a heavy iron gate bolted into the stone.
Prisoners must sit or lie on the stone floor, and are fed only once each day—a thin mushroom broth served in small clay bowls passed through gaps in the bars of the gate.
The drow have placed powerful wards on the slave pen to inhibit spellcasters and shield the area against scrying attempts.
Spells cast within the slave pen have no effect, and any slot or magic item charge expended to cast such a spell is consumed.
Creatures inside the slave pen can’t be targeted by any divination magic or perceived through magical scrying sensors.
The characters are held with ten other prisoners, captured during various raids and likewise awaiting transportation to Menzoberranzan:

• Buppido Talkative and cunning derro
• Prince Derendil Quaggoth who states he is an elf prince
• Eldeth Feldrun Shield dwarf scout from Gauntlgrym
• Jimjar Deep gnome with a gambling problem
• Ront Orc bully
• Sarith Kzekarit Drow
• Shuushar the Awakened Kuo-toa hermit and mystic
• Stool Myconid sprout
• Topsy and Turvy Deep gnome twins