The Omen Plague has other names. It is known as The Star Plague and even The Mundane Plague. It is still with us today, now known by the common name of the Shaking Death. To set the stage, the stars were aligned in all the wrong signs. Everyone new something bad was going to happen. When winter set in hard and early, they thought that was it. They were wrong.
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.