The Collision - The Impact Series, #2

As the world continues to reel from the shooting, Kate must race to save humanity from more horrific violence. After escaping an angry, dangerous mob, Kate Stellute and her neighbor Sinclair set out on a journey to stop Rex--and his kind-from unleashing more pain on the remaining population. The sinister otherworldly being has already made hundreds of millions of people turn their guns on themselves, and, amidst the suffering and death, no one can predict what he will do next. Kate knows she and Sinclair are up against an impossible deadline to stop Rex's mission before it's too late.
Relying on the biophysicist's late wife's mysterious research to determine what caused the alien's wrath, Kate and Sinclair join forces with NASA, a rogue Space Force agent, and two billionaire space bros. Together, they'll attempt to implement an improbable and risky plan. The unlikely team may just be the planet's last chance to save life as they know it.