Rago'ntarātmā रङ्गोऽन्तरात्मा॥ (sūtra III.10)

raṅgaḥ - stage of a theatre ; antar – within; ātmā – soul. 

Last aphorism said that an aspirant who is able to attain unmanā stage considers himself as an actor, not divulging his true nature. This sūtra further elucidates this concept. Antarātmā is the soul that is embedded in subtle bodies, as soul is invisible yet highly potent. The subtle soul is activated by entry of Self when the worldly drama begins to unfold. The soul as such is not affected by karmic qualities. However, the karmic embedment in the soul is the foundational cause for the types of activities that its body performs. The empirical soul is nothing but the manifestation of Śiva and realizing this truth is called Self realization. The activation of the soul happens by the infusion of puryaṣṭaka (five tanmātra-s – śabda, sparśa, rūpa, rasa and gandha with subtlest elements of antaḥkaraṇa viz. mind, intellect and ego). The quality of the puryaṣṭaka is not the same in everyone. It differs from person to person depending upon the quality of one’s karmic account. Karma unfolds through a body, still the Self within does not get involved with the unfoldment act. This reality is compared to an actor assuming different roles without affecting his own individual nature. This is further explained in the next sūtra.