The final incursion started and Earth-1610 started approaching Earth-616 while Iron Man and Steve Rogers kept fighting.
During the final incursion, Earth-1610's S.H.I.E.L.D. launches a full-scale attack on Earth-616, during which Stark and Rogers are crushed by a Helicarrier.
However, right before the final incursion between their universe and the Ultimate Universe, Sue's part of the ship becomes separated.
Months before the final Incursion happened, Briar established at least initial contact with several scientists which included Doctor Doom, Mister Fantastic, the High Evolutionary, Mister Sinister, Doctor Nemesis, and Dark Beast.