It's a thing that happens.

[Lysithea feels her way around the room clumsily for a few moments -- ]

Oh, forget it.

[Then lights it up with a ball of flame held in her hands. Patience is not a strong suit.]

Definitely no exit. ...And you're new here, aren't you? You have the look of somebody who's more surprised than he ought to be. It's a sort of trap - don't be too worried.