Cicero's "In Verrem" 2.2.162:
"per vim multitudinis factum esse videretur. cum hoc consilio statuas Centurpini publice sustulissent, audit Metellus; graviter fert; evocat ad se Centuripinorum magistratus et decem primos; nisi restituissent statuas, vehementer minatur."
"When, in pursuance of this design, the people of Centurpia had publicly destroyed his statues, Metellus hears of it. He is very indignant; he summons before him the magistrates and the ten principal citizens of the Centurpians. He threatens them with measures of great severity, if they do not replace the statues."
The last line:
"nisi restituissent statuas, vehementer minatur".
I first met this in Allen & Greenough section 592 "Informal Indirect Discourse". (A & G):
"He threatens them violently unless they should restore the statues.";
(A & G) continue: "Here the main clause, "that he will inflict punishment", is contained in 'minatur'".
This, then, is an example of the present tense ("minatur") being used to represent the future.
The problem, for me, is why is the pluperfect subjunctive (restituissent) being used to represent the future?
In the Wikipedia article "Latin Tenses", there are examples of the pluperfect subjunctive being used to represent the future e.g. as an epistolary verb: Roman letters were sometimes written in the past tense to benefit the receiver, for whom, upon receipt, the events described would already be in the past.
(WIKI) SECTION: "FORE UT":
"sperabam, cum has litteras accepisses, fore ut ea quae superioribus litteris a te petissemus impetrata essent." (Cicero Att. 16. 16E. 2) =
"I hope (epistolary imperfect) that by the time you receive this letter, what I requested from you, in my earlier letter, will have been granted."
Of course, the use of "fore ut" = "it would be the case that" will drive all the meanings/ tenses of the verbs into the future. The example from Verres is not a letter, but an oration; though, never delivered.
(WIKI) SECTION: "OTHER KINDS OF INDIRECT SPEECH":
"In other sentences the pluperfect subjunctive is a reflection of a future-perfect indicative, put into historic sequence. The original words of the following sentence would presumably have been":
"tu, si aliter feceris (future perfect), iniuram Caesari facies (future)."
A conditional sentence: simple conditions: the protasis will be completed before the apodosis can begin.) =
"If you do (will have done) otherwise, you will be doing Caesar a disservice."
CICERO'S ACTUAL INDIRECT DISCOURSE:
"eum, si aliter fecisset (pluperfect subjunctive), iniuram Caesari facturum dixit." (Cic. "ad Familiares" 8.11.2). =
"he said that if a man were to do otherwise, he would be doing Caesar a disservice."
Why/ how is a pluperfect subjunctive (an historic tense) a reflection of a future-perfect indicative (a primary tense) creating this confusion?
Why not just say:
"eum, si aliter facturus esset....dixit." =
"he said that if a man would do otherwise...";
giving the required sense of the future?
Similarly, returning to Verres, why was pluperfect subjunctive ("restituissent") used to represent the future, in what was meant to be an oration--the audience hearing it in their own present?