"Shadow Tag" follows Leo Vance, a down-on-his-luck document authenticator, who discovers a cryptic Cold War list hidden in a forged Civil War letter. Pursued by ruthless operatives, he teams up with insightful artist Mara. Their search leads them to Frank Novak, a veteran who has guarded the secret for decades—a failed CIA operation to extract his family from behind the Iron Curtain. To end the chase, they must use the past as bait, confronting the ghosts of a personal betrayal and discovering that some secrets survive not to harm, but to testify to the enduring cost of loyalty and love.