The sentence Miranda Jessicae imperat ut omnia narret Miranda orders Jessica that she tell all contains an Indirect Command. ut omnia narret that she tell all is an Indirect Command. A smoother English translation would be Miranda orders Jessica to tell all. In English the Verb in an Indirect Command is Infinitive, to tell, which in Latin would be narrare. In Latin, however, we instead use an Indirect Command, such ut narret that she tell. Except when we don’t.
There is another Verb that means the same (plus minusve more or less) as impero imperare imperavi imperatum and that Verb is iubeo, iubere, iussi, iussum. And yet, these Verbs demand different things from the words around them. Miranda imperat and Miranda iubet both mean Miranda orders. imperat, however, demands that the person you are ordering be placed in the Dative Case, while iubet demands they be placed in the Accusative. Miranda Jessicae imperat and Miranda Jessicam iubet, therefore, both mean Miranda orders Jessica. Moreover, while imperat demands ut narret that she tell, iubet demands (like English) narrare to tell. Both narret and narrare, of course, demand that their object, omnia all, be in the Accusative Case. And so, both Miranda Jessicae imperat ut omnia narret and Miranda Jessicam iubet omnia narrare mean Miranda orders Jessica to tell all.
There are a handful of Verbs that demand the same as iubet. Perhaps the most important is veto, vetare, vetui, vetitum to forbid. Miranda Jessicam vetat omnia narrare Miranda forbids Jessica to tell all. There are more, however, that behave like imperat, such as persuadeo, persuadere, persuasi, persuasum to persuade. Miranda Jessicae persuadet ut omnia narret Miranda persuades Jessica to tell all.
All three sit down around a table. ‘Who are you?’ Miranda asks Jessica without delay. ‘And why are you spending time here in town?’ She orders Jessica to immediately tell all.