The Jail

The Path

The party are taken to the jail along the catacombs. A system is setup here. At regular intervals stands a stoic looking guard. The guards stand on plinths and cast a new sphere of silence as members of the party progress down the tunnel. This tunnel is also embedded with low level anti-magic runes. This tunnel has a turn off after about 15 minutes of walking that will lead to a door on the left. This is the jail entrance.

Arcana Check These runes block powerful magic, at the density you see them here you conclude they would block all but cantrips and first level spells (Single Spell Point and bellow).

The Jail

You are blindfolded upon arriving at the entrance. The guards will then pass you onto what you can only assume are another set of guards. At which point you are escorted a short way to your holding cell.

Arcana Check From the cell all the stones you see also feature a carved anti-magic rune. It is clear great effort has gone into limiting the magic abilities of captives kept here. All magic even cantrips will fail here.

Above an 18 You suspect you could reduced the effectiveness of the runes if given enough time. At least to the point of being able to cast cantrips perhaps even low level spells.