Detect Thoughts
Once you have read a creature's surface thoughts, you can use an action to probe deeper into its mind. The creature makes a second Wisdom saving throw. On a successful save, you fail to read the creature's deeper thoughts and the spell ends. On a failure, you gain insight into the creature's motivations, emotional state, and something that looms large in its mind.
The creature then becomes aware you are probing its mind and can use an action to make an Intelligence check contested by your Intelligence check, ending the spell if it succeeds.
Additionally, you can use an action to scan for thinking creatures within range that you can't see.
Once you detect the presence of a thinking creature, so long as it remains within range you can attempt to read its thoughts as described above (even if you can't see it).
The spell penetrates most barriers but is blocked by 2 feet of stone, 2 inches of common metal, or a thin sheet of lead.