Stepping Off, by Jordan Sonnenblick

Fatefully, when Jesse was young, his parents bought a place in Pennsylvania in order to get away from NYC in the summers. In the neighborhood there were two girls of his age as well -- Ava and Chloe -- and they became close summer friends.  They never bothered to stay in touch during the year and they safely knew that they were friends and nothing more. But maintaining the friendship has grown harder as they have grown older.  Jesse fantasizes about going out with Ava, but knows she doesn't care for him in that way.

The summer of 2019 (between their sophomore and junior years) begins fortuitously with the three of them taking a ceremonial leap off of a nearby bridge together as part of a local rite of passage. But it is also a summer when they will take much riskier leaps together.  By the end of the summer, Jesse and Chloe find themselves together, but neither one knows what it means and things are left hanging.

Back home during the fall, Jesse's parents are separating and when he reaches out to Chloe for support, she doesn't answer.  So, he turns to Ava and things start developing between them.  Or do they?  It would seem that the friendships are changing, but the more they do so, they more a sense of dread develops that they are losing each other.  And then in March, everything changes as the world shuts down for Covid.

The arrival of Covid is interesting but not really organic to the story.  And the book loses its focus as Sonnenblick shifts the story to the challenges that the three of them face trying to sort out their feelings in isolation (not that any of it seems to stop them from spending a lot of time in close proximity). For that reason and others, there really isn't anything essential about the Covid Pandemic to the plot and it is actually distracting.  I’ve been waiting for a good historical YA set during the Pandemic.  This might have been it, but the first 2/3 of the novel isn’t about Covid and thus the story isn’t either.
 
I still loved the characters, their near misses and misunderstandings, and the anxieties about the changing nature of their friendships are topics that are all handled well.