The calling station who finally raises you has the nuts. Full stop.

Why they do it

They don't raise. That's the whole point. When they override their own passivity and actually put chips in with aggression, their hand is so strong they couldn't contain themselves. It's never a bluff.

The adjustment

Fold everything except the absolute top of your range. If you've got two pair and they raise the river, you're probably drawing dead. Just let it go.

What it's worth

Paying off the first raise from a calling station is one of the most expensive habits at $1/$2. One correct fold saves you $100+ every time.