The spirit of a creature trapped in amber cannot escape to it’s afterlife / next incarnation / whatever.
Such trapped spirits can be contacted by those who know the right rituals and magical power derived from them – typically the power to control one individual of that species.
Can by quite powerful if the creature is a colony insect (ant, bee, wasp, etc) – simply control the queen and you command the whole colony.
Half hour off the Harrow Road you find it, Fool's Grave. Amid an overgrown garden sits a single tombstone. Carved neatly into the weathered slab is the word "Fool," with a symbol underneath matching the signet ring you found.