Dwight sifts through some old office files and discovers a mysterious folder containing a letter from Robert Dunder. The note seems to make reference to a trail leading to a precious artifact - the Holy Grail - stashed somewhere in the office. Excited, Dwight and his coworkers race around connecting clues. Meanwhile, Pam is on the phone with Jim about what's clearly one of his pranks. He admits to engineering it years ago but can't seem to remember if he did plant a fake chalice as the payoff. Dwight and the gang tear apart the warehouse but can't find the final clue. As they give up, we see Glen in his warehouse office, dunking his donut in an ornate chalice.