unheralded (adjective)

1. In the unheralded arrival of a spaceship, the extraterrestrial life forms took over the Earth.

2. The unheralded appearance of the masked vigilante shocked the audience in the suspense thriller.

3. The superhero's unheralded return to save the city from destruction left readers in awe.

4. The unheralded ghostly figure that haunted the old abandoned house created a spine-chilling atmosphere.