Act as a seasoned poet with a knack for capturing raw human emotions. Compose a [free verse / rhyming] poem titled '[The Grudge's Shadow / Bitter Roots]' that delves into the lingering resentment between [two former friends / a betrayed lover / rival siblings]. Use vivid imagery to describe how the grudge festers like [a wound that never heals / a poison in the veins / a storm cloud overhead]. Incorporate at least one metaphor comparing the grudge to [a chainsaw cutting through trust / a wall built brick by brick / a fire that refuses to die]. The tone should be [melancholic / vengeful / resigned], and the poem should end with a striking line about [the weight of silence / the cost of holding on / the moment forgiveness seemed possible but slipped away].