In the present day, four teens: Elayah, Liam, Marcie, and Jorja, dig up the time capsule their parents' generation had buried during their high school days in the 1980s. But in addition to the expected usual ephemera: mix-tapes, Walkmans, photographs, letters, action figures, and other miscellaneous junk, they discover something more sinister-a large hunting knife wrapped with a note: "I'm sorry. I didn't mean to kill anyone." Is it a murder weapon?

As the action dramatically ricochets between the present day and 1986, the mystery gradually unfolds. And yes, someone was killed, and the knife was the murder weapon. The teens haven't just unearthed the time capsule, they've also unearthed painful secrets...