A living creature you can see seems to turn to living stone putting it in a state of suspended animation with 0 hit points and not needing to make any saving throws. When the spell ends, the creature automatically regains 1 hit point.

While in suspended animation, the creature cannot be damaged and any damage suffered will effect the caster. For every hour of concentration, the caster takes 4d6 necrotic damage. If the creature was unwilling or hostile, then the caster takes an additional 4d4 psychic damage (DC 18 Charisma saving throw for half damage).

If the spell is still in effect when the target is subjected to an effect that would kill it instantaneously without dealing damage, that effect is instead negated against the target, and the spell ends.