An inserted adverbial clause without a subject

In a dystopian near-future, government is a quaint concept, resources are coveted, and possession is 100% of the law. A handful of Families rule, jealously guarding what they have and exploiting the Waste who struggle to survive in their domains. Forever Carlyle defends her family's holdings through deception and force as their protector, their Lazarus. The 16 Families have gathered together in the exclusive luxury confines of Triton One to resolve the emerging conflict between Carlyle and Hock, and they've brought their Lazari with them. While Forever's romance with the Morray Lazarus, Joacquim, continues to blossom, she finds herself not only questioning her identity, but also her loyalty to her Family and her father, Malcolm, when orders her to kill her brother, Jonah.

I'd dearly love to know why the underlined inserted adverbial "when" clause doesn't have a subject.

Thank you in advance for your help.