An open problem in modal logic is to know if the fusion S4 S4 is the complete modal logic for the product of any two metric separable dense-in-themselves spaces. This would be settled, positively, if one could prove the following conjecture: When S4 is the complete logic for two complete atomic closure algebras, B and C, then the fusion S4 S4 is the complete modal logic for their product B ? C. This essay is an effort to give new garments to old results, in the hope that it would lead to a proof of this conjecture.