The Mental Prison card, Transmutation family, yin polarity, evokes a thought spinning and closing in the horizon. It signals a repetitive pattern limiting the range of possibilities you can perceive. Drawing this card invites you to identify the exact thought maintaining this closure.
In Oradia's mirror-card system, Mental Prison answers to Free Spirit: the two don't oppose each other, they answer each other, like two sides of the same movement.
This page gives the card's general meaning. In a real draw, the Mental Prison card is always read in relation to the other cards drawn and the intention set at the start — it's that combined reading, unique to each draw, that the online oracle develops.