You trespassed where you shouldn't have... an ancient grove guarded by a spirit of the wilderness. They give you an ultimatum; either you live there for the entire lifespan of a native plant before release, to repay your transgression... or you never leave this place alive. But they're benevolent, they'll let you pick your fate, and what you become. In your haste you glance around, your mind going blank so you point at the nearest tree! Something small, scraggly, surely as good a pick as any.

The spirits looks you over and nods. So be it!

Little did you realize the tree you so hastily chose can live for five thousand years or more...

... guess you'll have plenty of time to enjoy it~