UNSC and Convenant forces of Battle of New Mombasa ISOTED in 2022 Mombasa.

So in Halo 2 and Halo 3 (in 2552) : the Alien theocratic alliance known as Covenant launch a full major attack on Earth and local UNSC (United Nation Space Command) forces, quickly scattered. Battle of New Mombasa in Eastern Africa was a major engagement in the Covenant-Human war and quickly exposed the internal frailties of the alien alliance as well as its rather murky religious motivations (the search for remnants of an ancient space-faring civilization: the Foreuners).

Now let's imagine that following a Warp technology accident, all the Covenant forces but also the UNSC present during the battle find themselves propelled into contemporary Mombasa, that of 2022.