Detect thoughts

Detect thoughts is a divination spell that allows one to "listen" to surface thoughts.

Effect
The amount of information revealed depends on how long the caster studies a particular area or subject. The spell can penetrate barriers, but 30cm (1ft) of stone, 2.5cm (1in) of common metal, a thin sheet of lead, or 1m (3ft) of wood or dirt blocks it.

Arcane focus
A copper piece.