This two part story is very similar in concept to a story told in Action Comics 761, whereby Wonder Woman and Superman have to spend a thousand years together on their own batting a savage horde of creatures in an alternate reality. To their friends and loved ones however, only a brief moment in time has actually passed between them departing and returning. That story explored how their feelings towards each other would develop and how loyal Kal would be to Lois, and this Batman issues seems to explore very similar territory.