Bridge to Tomorrow is one of many side missions in Gravity Rush 2. It is available after finishing the tenth episode in the main storyline, No Messiah, No Message, and one of the last ones in the Jirga Para Lhao chapter of the game.
As Kat prepares for the upcoming town forum, she overhears a conversation between some soldiers of the old Garrison, who plan to bring Lisa down. Just as Kat interferes though, a bunch of Scarabs appear and start terrorizing the townsfolk.
With Kat's help, the divided military begrudgingly join forces to get the people to the safety of the airships nearby, but their path is constantly blocked by waves of Scarabs. Kat fights off every Scarab that appears as the military keeps the townsfolk calm. When they reach the airship, Kat still expresses concern over the old military trying to reclaim control over the city, but the blue masked soldier eases her fears by pointing out that the old military is only fighting in small numbers and pose no threat to the city whatsoever.
With this being an escort mission, your job is to lead the soldiers and some townsfolk to a nearby airship to evacuate. To do this, you will be fighting off waves of Scarabs when they appear but keeping them from getting too close to the crowd of people and raising their "Fear" gauge, at the same time. As you fight these enemies, Piercing Throw and Vortex Field will come handy, but you might want to engage in direct combat to keep the SP gauge high enough to use these techniques.