To honor the death of her best friend, teen Sienna signs up to do a triathlon and finds a connection with an unexpected training partner in this body-positive romance exploring first love, grief, perseverance and trusting in yourself.

Five months ago, Sienna Shoring lost her best friend, Stacey, to suicide. Now Sienna's back at school, struggling--and failing--to find her new place in the social hierarchy. Awkward and alone, Sienna is still dealing with her grief. When a package arrives for the "Try It Triathlon," which Stacey signed them up for as a joke, it's like receiving a message from the grave. Sienna has no experience with running or biking. And she doesn't even own a swimsuit. But she decides to take on the challenge in honor of her best friend, despite being a "fat girl." And when mysterious jock Blake Romano approaches her unexpectedly and offers to train with her, she can hardly say no. He seems to understand her in a way no one else does. But Blake has a secret that might just break Sienna's heart, even as he's winning it.