Mark knows grief. Ever since the accident that killed his twin sister, Grace, the only time he feels at peace is when he visits the bridge on which she died. Comfort is fleeting, but it's almost within reach when he's standing on the wrong side of the suicide bars. Almost.Grace's best friend, Hanna, says she understands what he's going through. But she doesn't. She can't. It's not just the enormity of his loss. As her twin, Mark should have known Grace as well as he knows himself. Yet when he reads her journal, it's as if he didn't know her at all.As a way to remember Grace, Hanna convinces Mark to complete Grace's bucket list from her journal. Mark's sadness, anger, and his growing feelings for Hannah threaten to overwhelm him. But Mark can't back out. He made a promise to honor Grace - and it's his one chance to set things right.