Why does water aid need the help of others in achieving their goal?

From the moment he becomes part of the group, Henry works to put himself in a leadership role. He ingratiates himself with Alyssa, knowing that she is an important part of the current leadership, and evaluates the others. He becomes friendly with Garrett who tells Henry that Kelton has a crush on Alyssa. Garrett spills another secret – that Kelton had once used a drone to spy on Alyssa. Knowing that Alyssa is unaware and that she will be horrified, Henry drops that information into a seemingly casual conversation. His only purpose is to drive a wedge between Alyssa and Kelton, and it works, but only for a while. Henry's evaluation of the group's dynamics is not thorough enough to realize that Alyssa and Kelton have already endured horrible situations together, cementing their relationship.