Solar Locket of the Father

A locked golden locket that hums with warmth when held toward the Sun. It cannot be opened in Act I — it is sealed by a father's magic — but while attuned, the wearer gains a +1 bonus to saving throws against spells, and once per long rest they may cast the Shield spell as a reaction without components. The locket's warmth is unmistakably a father's, and it will open only in a later act, at the heart of the Sun's domain.